Apple Music

Hello psmittay,

Thank you for reaching out to Apple Support Communities.

These steps may be able to help:

"If you still can't share a subscription

After you set up Family Sharing, eligible subscriptions are automatically shared with your family members. If your family members can't access a subscription, here's what to do:

• If the subscription is an individual or student subscription, upgrade your subscription to a family plan. 
• Subscriptions that aren't made by Apple, also called third-party subscriptions, might not be eligible to share. If a subscription is shareable, you see a Share with Family option when you go to Settings > [your name] > Subscriptions and tap the subscription."

More details can be found here: Add a family member to your subscriptions from Apple

If the issue persists, can you provide a few more details? Are you able to share Apple Music with other members of family sharing? Also, which iOS version do you and your family member have installed?

Cheers!