How to delete account completely

1. Head to Apple’s data and privacy webpage login
2. Log in to the account you’d like to delete
3. Toward the bottom, click on Request to delete your account
4. Make sure you want to delete your account and double-check backups of your data
5. Double check if you have any subscriptions with your Apple ID
6. Choose a reason for deleting your account, click Continue
7. Follow the remaining prompts to permanently delete your Apple ID account

In case the link didn't work

https://9to5mac.com/2018/12/21/delete-apple-id-account/