Hi @Saqlain burki
Welcome to the Sonos Community!
Please log in at https://www.sonos.com/login and click on Profile. Check your address (especially your country) and if it needs changed, please do so (there’s an Edit button at the top right).
This will of course depend on you being in a region supported by Apple Music - you can check under Availability on this page: https://support.sonos.com/services/apple-music.
Please note that it may take an hour or two for the change to be registered by the app and for Apple Music to be made available for addition to your Sonos system.
I hope this helps.
"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein