2 phones on 1 apple id

See the following Apple articles:

Set up Family Sharing -> Set up Family Sharing - Apple Support

What is Family Sharing? -> What is Family Sharing? - Apple Support

Make sure that each family member has a unique Apple ID

Make sure that each family member has a unique Apple ID - Apple Support

You don't.

Each person needs their own Apple ID.

wildsue wrote:

Thanks but Dang! This is for my 79 year old husband. Teaching him how to use it can be a nightmare

When sharing an Apple ID, notifications, continuity-related features, and two-factor authentication can (and variously will) go to the “wrong” phone. Contacts, photos, and the rest all get intermixed, too.

Been to a somewhat similar place on occasion, too. Most recently, a big-buttoned feature phone was a better fit for their needs, and a big-buttoned cordless phone as their traveling ranges decreased. If they’re repeating questions and forgetting information, or if they’re getting frustrated with the iPhone, consider a feature phone or a cordless phone. (A few years ago, I had trouble finding a feature phone, too. Hopefully that’s gotten easier.) But you know the people involved, and know your situation best.

Sharing an Apple ID always ends badly. Always.

Two phones on one Apple ID for one user works just fine.

Two phones, two users, one Apple ID, not so much.