As a late millennial and a programmer, I've got you.
So when you request a web page, before anything else, the server gives you a 3 digit status code.
100s means you asked for metadata
200s mean it went ok
300s means you need to go somewhere else (like for login, or because we moved things around)
400s mean you messed up
500s mean I messed up
So this is in the 400s. Each specific code means something - you've probably seen 404, which means you asked for a page that isn't there. And maybe 405, which means you're not allowed to see this
418 means you asked for coffee, but I'm a teapot
One of my favorite things to do with chat gpt is having it rewrite things as Trump. I wasn't interested in rereading the constitution a second ago, but it's going to be tremendous, you wouldn't believe how great it's going to be