How can I remove my debit card from my I-pad

You must always have at least one payment method registered with your AppleID account - against which any Apps, Media or Subscription services that are purchased from Apple will be charged.

You can remove additional methods from your AppleID - subject to having at least one payment method. If you only have one registered payment method, you must add another before the existing entry can be removed from the AppleID account.

You may find these support pages to be helpful:

If you need to change or update your Apple ID payment method - Apple Support

Add a payment method to your Apple ID - Apple Support

Remove a payment method from your Apple ID - Apple Support

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

Where on your iPad do you want to remove it form exactly?

You can remove it from the Wallet section in the Settings App ➜ Wallet & Apple Pay, tap the card in the list, then scroll all the way to the bottom, and tap on "Remove Card".

This is the only place a card actually resides on your iPad.

If the card was added to your Apple ID as suggested by the support document you posted from, then its not actually on your iPad directly. It lives on your Apple ID. If you are planning on giving the iPad away, then you would need to erase it, and remove your account from it entirely, not just your card. Removing the card from the Apple ID, removes it from all devices using that Apple ID.

To remove a payment method from an Apple ID, follows the steps in the link below.

click here ➜ Remove a payment method from your Apple ID - Apple Support

If you have active subscriptions, pre-orders or pending payments, you must make sure there is a valid and verified payment method on file before removing one. Accounts with active subscriptions, pre-orders or pending payments cannot be left without a payment method on file.