Some of the blog post and questions about Square mention a token prefixed with ‘sq0atp-’ (e.g. Keeping Your Customers up to date.), but I don’t think I am able to generate such a token? My personal access tokens look random. Was this changed at some point, and are my tokens interchangeable with these?
Yes, the tokens were changed to their current style after that blog post. That post is almost 5 years old and a lot has changed.