I don’t have a paid developer account. I’ve logged into the developer web site, but not paid for it. On my iPad and iPhone the option to enable iOS 16 developer beta updates showed up after upgrading to iOS 16.4. It doesn’t seem like it should be as I’ve never had a beta installed on either.
Meanwhile, a friend of mine paid for the developer account but doesn't see the option. He only sees the public beta choice. And Apple support is not helping at all. This whole thing is pretty messed up.