Changing country

You need a zero account balance and you need to cancel all your subscriptions. If you have cancelled all subscriptions, but some haven’t expired, contact iTunes Support. You need a credit card issued by a bank in the country the store is in, and you need a billing address in that country. If you have an account balance, either buy something more expensive and pay the balance with a credit card or contact iTunes Support and ask them to zero balance your account.

If necessary, contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.

iTunes Store - Contact Us - Official Apple Support. https://support.apple.com/en-euro/itunes-contact

iTunes Support – world wide https://support.apple.com/choose-country-region/itunes

Here's a guideline for doing that:

Change your Apple ID country or region - Apple Support