QUESTION html form with post method

[beaksdale]

My guess is there is a redirect occurring before your code runs, so you are losing the data.

learn how to use your browsers development tools to inspect the headers etc.
chrome F12

Thanks for the suggestion. I've looked at Chrome's developer tools and while I couldn't work out if it was redirecting I did notice that it wasn't being treated as form data but request payload, which was because I was using enctype text/plain for the form instead of the default.