Removing pending charges from the App Store

It is not possible to remove a Pending Charge as it has already been authorized with the double click of the side button, followed by authentication with Face ID/Touch ID or Passcode with the terms of the charge on the screen.

All you can do is provide the funds needed to process the transaction, then request a refund. In most cases all transactions in the App Store are final due to the required steps to authorize those charges, but at times Apple may provide a compassionate refund.

Request a refund for apps or content that you bought from Apple - Apple Support

This Support Article might be helpful for how to pay that pending charge:

If a message says 'billing problem with previous purchase' or 'verification required' - Apple Support

They will tell you to pay the bill and then file for a refund then they will fix the problem but that there’s nothing they can do to help.