How do I check bank account for Apple app subscription payments

This document explains how to add a payment method to your Apple Account on a Mac, Apple mobile devices, PC, or online ➔ Add a payment method to your Apple Account - Apple Support

On an iPhone or iPad (note that the details may vary slightly depending upon which iOS version you are running) :

1. Open the Settings app.

2. Tap your name.

3. Tap Media & Purchases (or Payment & Shipping). You might be asked to sign in with your Apple ID.

4. Tap Manage Payments. Depending upon the iOS version you use you might not see this step.

Go to Settings, the tap your Apple account name at the top, then tap Payment and Shipping. You’ll see what payment method(s) you have set up.