how can i fix this

miguelr18.

We appreciate your patience. Knowing that the promotion came from Best Buy helped us find the specifications for their Apple Music promotion. It looks like the offer may be for new Apple Music subscribers only. Check the “Specifications” section of your card here:

Apple Free Apple Music for 6 months (new subscribers only) - Best Buy

This means that you won’t be eligible to redeem the code if you are now (or ever have been) subscribed to Apple Music. If you have any questions about the code, you should see a "Chat Now" option to get in touch with Best Buy support on that page.

Warmest Regards.

Hello, miguelr18.

Thank you for posting in Apple Support Communities. We understand that you’re experiencing an issue redeeming a code in your Apple Music, and we want to make sure we fully understand.

What type of card are you attempting to redeem? Is it possible that the code you are using has already been redeemed? 

This article may help:

If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card - Apple Support

If not, tell us more.

What type of code will are you attempting to redeem?

Have you redeemed these types of codes before?

Warmest Regards.