I got all the way to the “Go Public” step, and bam …
Business verification required to go live
Before you can go live, an app admin must complete business verification. Once your business account has been verified, you can come back to this page and go live. Learn more about business verification.
Business verification is hopelessly out of reach in my case, because I don’t have a legally incorporated business:
I googled and found that this change took place just 3 months ago, i.e. February 2023:
I guess I’m permanently screwed. Forget Facebook login for me. Small, informal websites are just banned from the playground now. 
