I see you want to empty your account balance. The people on this forum—other users like yourself—cannot do this for you but there are TWO ways you can try:
#1. If you still have a valid credit or debit card from your original country, purchase an item for slightly more than your balance. The remainder will be billed to your card, leaving you with nothing in your account balance. This is the only solution for you to empty your balance if cannot contact Apple Support. This method is the easiest and has the additional benefit that you get to use your money for something for yourself instead of simply giving it to Apple.
#2. Ask Apple Support to remove and keep the balance. Live support is not available in all countries.
- Special balance-emptying chat contact link at the bottom of this support article --> Check your Apple Account balance - Apple Support
- Link to chat with support for Apple Accounts —> https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0998&symptom_id=20198
- General Apple support and service contact ➔ Contact Apple Support - Apple Support If live support options are available they will show near the bottom left. Telephone numbers may only work when calling from the same country.
- With an iPhone, iPad, or Vision, you may be able to chat using the Apple Support App if it is available in your country —> https://apps.apple.com/app/apple-support/id1130498044
If you can neither add a payment method nor contact Apple, your alternative is to create a new Apple Account when you are in the new country. Avoid doing that if at all possible. It may cause many complications with your current account content.
When asking about this because you are changing regions, take a look at this article:
Change your Apple Account country or region - Apple Support