I paid for Apple one family but my husband can’t connect

That suggests an issue with the connection, not that it's not actually being shared.

Make sure he has a functional wi-fi or cellular data connection. If on Cellular Data, make sure the Music App is turned on for it in Settings ➜ Cellular.

Or Settings ➜ Music ➜ Cellular Data.

Why not? What happens when he tries?

What device is he trying this on?

Does the subscription appear as shared for him?

Did he have his own Apple Music subscription before this that he cancelled?