Make sure that you're eligible
Visit apple.com/promo to check that the offer for a promotional trial of Apple TV+ is still current. Most offers are available only for a limited time. To make sure that you or the product that you bought qualifies for the offer, read the terms and conditions.
If your offer isn't listed, check if the offer came from another company. Contact that company for help with redeeming the offer.
Sign in on the eligible device
To redeem some promotions, you must be signed in with your Apple ID on the eligible device. Make sure that you're using the eligible device, then sign in with your Apple ID. Then try to redeem the promotion again.
If your eligible device is a Mac and you have just set it up, you might need to wait at least 4 hours for the offer to appear.
Update the software on your device
Check if you or a family member already redeemed the offer
If you or a family member already redeemed the offer, you can't redeem it again. To see if you already redeemed the offer, see your subscriptions.
Contact Apple Support
If you tried these steps and you still can't redeem the offer, contact Apple Support.