I have no idea what you're getting at

When you get HTTP::Message content must be bytes it means you must only give it bytes not text, in other words, don't use decoded_content

If you're saying that using ->content you still get this error(content must be bytes), that means $response isn't the culptrit, then you need to identify which parameter is triggering it by process of elimination, and make some bytes (encode)

perlunitut: Unicode in Perl#encoding