Add user to my apple tv+ subscription

To share e.g. an Apple TV+ subscription with family members, one of the group members has to set up the Apple Family Sharing group on their iPhone, iPad, or Mac. Each group member needs to have their own Apple ID account. The organizer invites the others through their accounts. Once accepted, the Apple TV+ subscription is automatically shared. Each group member accesses the Apple TV+ service through their own account. The organizer and the subscriber do not necessarily have to be the same person.

About Family Sharing - Apple

Learn about what you can do with Family Sharing - Apple Support

Set up Family Sharing - Apple Support

Add a family member to your shared subscriptions - Apple Support