I'm trying to link my steam account to my profile, but I'm not sure what information to put in. Do I put in my username? Because that doesn't seem to work.

I put my Steam user name in the "Steam" social box and it worked fine. i.e. I wrote "TheOreo321" and the link filled the rest.

Huh. That's weird. I'll try it again.

The steam field is looking for your community ID which is the numbers (or custom url if you set one) when you go to your steam profile page

Thank you so much!