Originally Apple Music was only free for 6 months for new customers, noticed it says existing too so I signed up.
Text 'Music' to 150
If you already have or have previously had Apple Music tho it seems to glitch and customer service have to add it manually.
Customer service added it for me no issue as the automated system said I wasn't a pay monthly customer which was wrong.
EE CUSTOMERS ONLY.
- Zetec Andy