Download the PDF of the Previewed Invoice

var options = new RestClientOptions("https://apitest.nilvera.com")
{
    MaxTimeout = -1,
};
var client = new RestClient(options);
var request = new RestRequest("/einvoice/Send/Model/Download/Pdf", Method.Post);
request.AddHeader("Content-Type", "application/json");
request.AddHeader("Authorization", "Bearer <API KEY>");
var body = @"{
  ""EInvoice"": {
    ""InvoiceInfo"": {
      ""UUID"": ""3fa85f64-5717-4562-b3fc-2c963f66afa6"",
      ""TemplateUUID"": ""3fa85f64-5717-4562-b3fc-2c963f66afa6"",
      ""TemplateBase64String"": ""string"",
      ""InvoiceType"": ""SATIS"",
      ""InvoiceSerieOrNumber"": ""string"",
      ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
      ""CurrencyCode"": ""string"",
      ""ExchangeRate"": 0,
      ""InvoiceProfile"": ""TEMELFATURA"",
      ""DespatchDocumentReference"": [
        {
          ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
          ""Value"": ""string""
        }
      ],
      ""OrderReference"": {
        ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
        ""Value"": ""string""
      },
      ""OrderReferenceDocument"": {
        ""ID"": ""string"",
        ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
        ""DocumentType"": ""string"",
        ""DocumentTypeCode"": ""string"",
        ""DocumentDescription"": ""string"",
        ""Attachment"": {
          ""Base64Data"": ""string"",
          ""MimeCode"": ""string"",
          ""FileName"": ""string""
        }
      },
      ""AdditionalDocumentReferences"": [
        {
          ""ID"": ""string"",
          ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
          ""DocumentType"": ""string"",
          ""DocumentTypeCode"": ""string"",
          ""DocumentDescription"": ""string"",
          ""Attachment"": {
            ""Base64Data"": ""string"",
            ""MimeCode"": ""string"",
            ""FileName"": ""string""
          }
        }
      ],
      ""TaxExemptionReasonInfo"": {
        ""KDVExemptionReasonCode"": ""string"",
        ""OTVExemptionReasonCode"": ""string"",
        ""AccommodationTaxExemptionReasonCode"": ""string""
      },
      ""PaymentTermsInfo"": {
        ""Percent"": 0,
        ""Amount"": 0,
        ""Note"": ""string""
      },
      ""PaymentMeansInfo"": {
        ""Code"": ""string"",
        ""ChannelCode"": ""string"",
        ""DueDate"": ""2024-04-03T06:27:33.163Z"",
        ""PayeeFinancialAccountID"": ""string"",
        ""Note"": ""string""
      },
      ""OKCInfo"": {
        ""ID"": ""string"",
        ""IssueDate"": ""2024-04-03T06:27:33.163Z"",
        ""Time"": ""string"",
        ""ZNo"": ""string"",
        ""EndPointID"": ""string"",
        ""DocumentDescription"": ""string""
      },
      ""ReturnInvoiceInfo"": [
        {
          ""InvoiceNumber"": ""string"",
          ""IssueDate"": ""2024-04-03T06:27:33.163Z""
        }
      ],
      ""AccountingCost"": ""string"",
      ""InvoicePeriod"": {
        ""StartDate"": ""2024-04-03T06:27:33.163Z"",
        ""StartTime"": ""2024-04-03T06:27:33.163Z"",
        ""EndDate"": ""2024-04-03T06:27:33.163Z"",
        ""EndTime"": ""2024-04-03T06:27:33.163Z"",
        ""DurationMeasureValue"": 0,
        ""Description"": ""string""
      },
      ""SGKInfo"": {
        ""RegisterName"": ""string"",
        ""DocumentNumber"": ""string"",
        ""RegisterCode"": ""string""
      },
      ""Expenses"": [
        {
          ""ExpenseType"": ""HKSKOMISYON"",
          ""Percent"": 0,
          ""Amount"": 0
        }
      ],
      ""LineExtensionAmount"": 0,
      ""GeneralKDV1Total"": 0,
      ""GeneralKDV8Total"": 0,
      ""GeneralKDV18Total"": 0,
      ""GeneralKDV10Total"": 0,
      ""GeneralKDV20Total"": 0,
      ""GeneralAllowanceTotal"": 0,
      ""PayableAmount"": 0,
      ""KdvTotal"": 0
    },
    ""CompanyInfo"": {
      ""TaxNumber"": ""string"",
      ""Name"": ""string"",
      ""TaxOffice"": ""string"",
      ""PartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""AgentPartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""Address"": ""string"",
      ""District"": ""string"",
      ""City"": ""string"",
      ""Country"": ""string"",
      ""PostalCode"": ""string"",
      ""Phone"": ""string"",
      ""Fax"": ""string"",
      ""Mail"": ""string"",
      ""WebSite"": ""string""
    },
    ""CustomerInfo"": {
      ""TaxNumber"": ""string"",
      ""Name"": ""string"",
      ""TaxOffice"": ""string"",
      ""PartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""AgentPartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""Address"": ""string"",
      ""District"": ""string"",
      ""City"": ""string"",
      ""Country"": ""string"",
      ""PostalCode"": ""string"",
      ""Phone"": ""string"",
      ""Fax"": ""string"",
      ""Mail"": ""string"",
      ""WebSite"": ""string""
    },
    ""BuyerCustomerInfo"": {
      ""TaxNumber"": ""string"",
      ""Name"": ""string"",
      ""TaxOffice"": ""string"",
      ""PartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""AgentPartyIdentifications"": [
        {
          ""SchemeID"": ""string"",
          ""Value"": ""string""
        }
      ],
      ""Address"": ""string"",
      ""District"": ""string"",
      ""City"": ""string"",
      ""Country"": ""string"",
      ""PostalCode"": ""string"",
      ""Phone"": ""string"",
      ""Fax"": ""string"",
      ""Mail"": ""string"",
      ""WebSite"": ""string""
    },
    ""ExportCustomerInfo"": {
      ""TaxNumber"": ""string"",
      ""LegalRegistrationName"": ""string"",
      ""PersonName"": ""string"",
      ""PersonSurName"": ""string"",
      ""Address"": ""string"",
      ""District"": ""string"",
      ""City"": ""string"",
      ""Country"": ""string"",
      ""PostalCode"": ""string"",
      ""Phone"": ""string"",
      ""Fax"": ""string"",
      ""Mail"": ""string"",
      ""WebSite"": ""string""
    },
    ""TaxFreeInfo"": {
      ""TouristInfo"": {
        ""Name"": ""string"",
        ""SurName"": ""string"",
        ""CountryCode"": ""string"",
        ""PassportNo"": ""string"",
        ""PassportDate"": ""2024-04-03T06:27:33.163Z"",
        ""AddressInfo"": {
          ""Address"": ""string"",
          ""District"": ""string"",
          ""City"": ""string"",
          ""Country"": ""string"",
          ""PostalCode"": ""string"",
          ""Phone"": ""string"",
          ""Fax"": ""string"",
          ""Mail"": ""string"",
          ""WebSite"": ""string""
        },
        ""FinancialAccountInfo"": {
          ""BankName"": ""string"",
          ""BranchName"": ""string"",
          ""ID"": ""string"",
          ""CurrencyCode"": ""string"",
          ""PaymentNote"": ""string""
        }
      },
      ""TaxRepresentativeInfo"": {
        ""RegisterNumber"": ""string"",
        ""Alias"": ""string"",
        ""Address"": {
          ""Address"": ""string"",
          ""District"": ""string"",
          ""City"": ""string"",
          ""Country"": ""string"",
          ""PostalCode"": ""string"",
          ""Phone"": ""string"",
          ""Fax"": ""string"",
          ""Mail"": ""string"",
          ""WebSite"": ""string""
        }
      }
    },
    ""InvoiceLines"": [
      {
        ""Index"": ""string"",
        ""SellerCode"": ""string"",
        ""BuyerCode"": ""string"",
        ""Name"": ""string"",
        ""Description"": ""string"",
        ""Quantity"": 0,
        ""UnitType"": ""string"",
        ""Price"": 0,
        ""AllowanceTotal"": 0,
        ""KDVPercent"": 0,
        ""KDVTotal"": 0,
        ""Taxes"": [
          {
            ""TaxCode"": ""string"",
            ""Total"": 0,
            ""Percent"": 0,
            ""ReasonCode"": ""string"",
            ""ReasonDesc"": ""string""
          }
        ],
        ""DeliveryInfo"": {
          ""GTIPNo"": ""string"",
          ""DeliveryTermCode"": ""string"",
          ""TransportModeCode"": ""string"",
          ""PackageBrandName"": ""string"",
          ""ProductTraceID"": ""string"",
          ""PackageID"": ""string"",
          ""PackageQuantity"": 0,
          ""PackageTypeCode"": ""string"",
          ""DeliveryAddress"": {
            ""Address"": ""string"",
            ""District"": ""string"",
            ""City"": ""string"",
            ""Country"": ""string"",
            ""PostalCode"": ""string"",
            ""Phone"": ""string"",
            ""Fax"": ""string"",
            ""Mail"": ""string"",
            ""WebSite"": ""string""
          }
        },
        ""ManufacturerCode"": ""string"",
        ""BrandName"": ""string"",
        ""ModelName"": ""string"",
        ""Note"": ""string"",
        ""OzelMatrahReason"": ""string"",
        ""OzelMatrahTotal"": 0,
        ""VatAmountWithoutTevkifat"": 0,
        ""AdditionalItemIdentification"": {
          ""TagNumber"": ""string"",
          ""OwnerName"": ""string"",
          ""OwnerTaxNumber"": ""string""
        }
      }
    ],
    ""Notes"": [
      ""string""
    ]
  },
  ""CustomerAlias"": ""string""
}";
request.AddStringBody(body, DataFormat.Json);
RestResponse response = await client.ExecuteAsync(request);
Console.WriteLine(response.Content);