Hello, i want to delete my billing information on the App Store, but i cannot.

Do you have any active subscriptions? If so you can’t delete your billing info without canceling your subscriptions first.

https://support.apple.com/en-us/HT203905

Hello APHN,

Click on the first link for assistance if you can't remove your last payment method or use no payment method with your Apple ID

[formerly: If you can‘t choose None when you edit your Apple ID payment information]

"Learn why you can't use your Apple ID without a payment method in the App Store, iTunes Store, and more." - https://support.apple.com/HT203905 - also make sure you don't have any active subscriptions, are set as the Family Organizer for a Family Sharing plan, or owe any money for past purchases.