Might be select account only. Worth having a look.
T&Cs: Eligibility Criteria: The promotion is open to members of Priority who are UK residents age 16+.
Reward Start and End Dates: Reward is valid from 08/06/21 - 21/06/21, while stocks last - subject to availability.
Redemption Instructions: To redeem, tap ‘USE NOW’ and you will be directed to the Apple Music website.
Reward Goods/Services: Reward entitles you to receive up to six months of Apple Music for free. Customers who have not tried Apple Music before can redeem up to six months free, that is three month free trial, plus the additional three month offer code with Priority. Customers who are existing Apple Music users or have used up the three month free trial in the past will be able to redeem three months free.
These terms and claim instructions incorporate and apply in addition to the Priority App T&Cs, which can be found under your app ‘Settings’.