Make sure you have an Apple Music Family subscription
Set up Family Sharing on your iPhone, iPad, or Mac
Add family members to your Family Sharing group
Turn on Purchase Sharing if needed
Open Settings
Tap your name
Tap Family Sharing
Tap Apple Music
Follow the prompts to invite or confirm family members
Have each family member accept the invitation
On each family member’s device, open the Music app
Sign in with their own Apple ID
Start using Apple Music with the shared family subscription