Apple ID verification code is required but nowhere to put the password!

I've picked up on this old thread for the same (original) problem - says an Apple ID verification code is required but nowhere to put the password or code (sequentially or otherwise) - ie there is literally no place to type this!

Went to iCloud account details, did all the steps to verify, including password/code and that's fine, I'm authorised but I've still got the box saying 'Apple ID verification code is required' with nowhere to type it! Only other option seems to be to permanently sign out - if I'm willing to delete all my other contacts/info.

Infuriating and amazingly stupid for a company that's supposedly full of smart people and so surprising that they haven't fixed this after so many years and so many other users with same problem.