Apple Music Subscription

My family has an apple music subscription (Family plan). I recently got a MacBook Air and every time I try to play music it says join apple music. I have tried multiple different steps but nothing is allowing my MacBook to connect to our current apple music plan. I have the sync thing turned on and purchase sharing and everything but regardless it still tells me I need to sign up. My apple ID is showing in the family plan as well and it's the same one I have connected to this MacBook.