I purchased a new phone from Sprint, recently I thought I had a subcription for Apple TV for a year?

When did you make the purchase? T-Mobile and Sprint have merged, and the Sprint brand was discontinued early August.

If you bought a new iPhone from an Apple Authorized Reseller (including former Sprint), the your purchase may qualify for the year offer. One of the conditions is, that you have to redeem the offer within 3 months.

Apple TV+ - One Year Offer - Apple

This guide has the steps on how to redeem, all the details like conditions, and an eligibility check.

When does my offer expire?

You have three months after first setting up your device to take advantage of your free year of Apple TV+.

If you qualify, and if you did as described in the guide, and you still do not get to see the year offer, then contact Apple Support. They can assist in getting you the service, if needed using activation codes.