How to send multipart/form-data with Delphi using THTTPClient

formData.pas

uses System.Net.HttpClient, System.Net.Mime;

function Send: string;
var
  LRequest: THTTPClient;
  LFormData: TMultipartFormData;
  LResponse: TStringStream;
begin
  LRequest := THTTPClient.Create;
  LFormData := TMultipartFormData.Create();
  LResponse := TStringStream.Create;
  try
    LFormData.AddField('myJson', '{"id":1,"user":"Vinicius Sanchez"}');
    LFormData.AddFile('myFiles', 'C:\Samples\FormData\File.pdf'); // You can also use the AddStream method if it's available
    LRequest.Post('myUrl', LFormData, LResponse);
    Result := LResponse.DataString;
  finally
    LFormData.Free;
    LResponse.Free;
    LRequest.Free;
  end;
end;

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