how do i get annual subscription for apple music ?

Maybe check that Apple supports music subscriptions in your country or. region

Availability of Apple Media Services – Apple Support

NB: You can also click the link in the article to see what payment methods Apple accepts in your country or region.

Or

If you already have / had a music subscription:

you might want to try the steps in this online article to see if they work for you:

https://www.tunefab.com/apple-music/get-apple-music-annual-subscription.html

Else:

To start a new trial subscription with an initial free period:

Apple Music - Apple

Hope this helps :-)

PS: More info:

Join Apple Music on your iPhone, iPad, iPod touch, Mac, or PC - Apple Support