use LWP::UserAgent;
use HTTP::Headers;

my $headers  = HTTP::Headers->new();
$headers->header('Content-Disposition', 'form-data; name="fileBody"; filename="[Placeholder file name]");
$headers->header('Content-Type', 'text/plain');
my $ua = LWP::UserAgent->new(
    default_headers => $headers,
);
my $response = $ua->post($URL, Content => $content_of_your_file);