HTTP::Tiny::Multipart3pm

    use HTTP::Tiny;
    use HTTP::Tiny::Multipart;
  
    my $http = HTTP::Tiny->new;
  
    my $content = "This is a test";
  
    my $response = $http->post_multipart( 'http://localhost:3000/', { 
        file => {
            filename => 'test.txt',
            content  => $content,
        }
    } );

creates this request

  POST / HTTP/1.1
  Content-Length: 104
  User-Agent: HTTP-Tiny/0.025
  Content-Type: multipart/form-data; boundary=go7DX
  Connection: close
  Host: localhost:3000
  
  --go7DX
  Content-Disposition: form-data; name="file"; filename="test.txt"
  
  This is a test
  --go7DX--

And

    use HTTP::Tiny;
    use HTTP::Tiny::Multipart;
  
    my $http = HTTP::Tiny->new;
  
    my $content = "This is a test";
  
    my $response = $http->post_multipart( 'http://localhost:3000/', { 
        file => {
            filename => 'test.txt',
            content  => $content,
            content_type  => 'text/plain',
        },
        testfield => 'test'
    } );

creates

  POST / HTTP/1.1
  Content-Length: 104
  User-Agent: HTTP-Tiny/0.025
  Content-Type: multipart/form-data; boundary=go7DX
  Connection: close
  Host: localhost:3000
  
  --go7DX
  Content-Disposition: form-data; name="file"; filename="test.txt"
  Content-Type: text/plain
  
  This is a test
  --go7DX
  Content-Disposition: form-data; name="testfield"
  
  test
  --go7DX--