Help! Foibles trying to change to Apple Music Family

...so my kid and brother and wife can stream, and cut off 2 Spotify* accounts. To change to Apple Music Family from individual it seems I must
1) make iCloud into Family Sharing, and THEN
2) change the Apple Music account to Family.
Unfortunately, when I try to do #1, it keeps referring me to update my payment method, which in Settings seems fine (it's set to PayPal as it has been for years).
????


*(primarily because I had a bunch of problems getting that to play in one car, and now have CarPlay in another)

 

Have you got any further enabling Family Sharing? I use Family Sharing with Apple Music family membership here and it was fairly simple to set up.

I remember having to confirm payment details, as Family Sharing has everyone using the same payment method for iTunes purchases, subscriptions etc. Once set up, Family Sharing invites were issued and accepted, Apple Music Family Sharing just worked for everyone. All behaved flawlessly ever since. Also a serious CarPlay user in conjunction with Apple Music here - asking for Floyd or my Pick Of The Pops playlists in the car never gets old

We also share iCloud storage [200GB) to back up devices, store photos etc.

 

I have Apple paid by PayPal so that once upon a time I could have a developer who was doing iPod/iPhone integration work for me could buy stuff from the Apple Store (he was in Canada).

I gave up on this-got my kid a college Spotify/Hulu for $4.99 and my brother has not gotten into streaming. So for now, the heck with it. 'Course now my wife wants to listen to music while jogging-but maybe FM is OK she says