How to change my region and payment method

The article "Change your Apple ID country or region" describes how to change your country setting on everything using your Apple ID, and the requirements and results of doing this --> Change your Apple ID country or region - Apple Support

Here is how you update your payment method on an iPhone or iPad:

1. Open the Settings app.

2. Tap your name.

3. Tap Payment & Shipping. You might be asked to sign in with your Apple ID.

4. Tap Add Payment Method, enter the new payment method, then tap Done.

5. Tap Edit.

6. Tap the red delete button next to the old payment method, then tap Delete.