Q: hello, im paying a familiar suscription for apple music and i cant include my sons iphone

Why? Is there a specific error message that you receive?

Have you followed the steps here?

Set up Family Sharing - Apple Support

valeherc wrote:

 

i canot include my son in the sharing family.

 

Why not?  What happens when you try?  If you want help then you need to provide details as we're not psychic.

You can unsubscribe at any time.

AFAIK, all subscriptions require a credit card to be on file, in case gift card credits run out. You wouldn't want to loose access to your files just because you forgot to replenish your credit.