Apple Music subscription automatic renewal

The Apple Music subscription will auto-renew each month, if the fees can be payed with one of the valid payment methods.

If you pay this subscription with Apple ID account balance, then you should have the needed funds on the Apple ID account on the due day. You will not be asked for it each time; you should have it ready before that time. If the payment fails, then the subscription will be suspended (to avoid a debt).

If you have a card that supports automatic online payments (without needing confirmation each time), then that would be much easier for subscription fees.

Payment methods that you can use with your Apple ID - Apple Support

Apple Pay is quite different from a card linked to your Apple ID for iTunes Store purchases.

See if any issues are mentioned for your current payment method.

For further assistance, contact the iTunes Store staff. They may be able to look at specifics for your account.