I see you want to empty your account balance. This is not something the people on this forum—other users like yourself—can do for you. You can ask Apple Support to remove and keep the balance. Use this link Apple provides to take you directly to the managing and editing an Apple Account people who will do this for you --> https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0998&symptom_id=20198
This is more direct than using Official Apple Support which will just eventually lead you to the same place after some searching.
If the above direct link does not work for you, go to https://getsupport.apple.com/?s=n , enter “empty balance” or “zero balance” in the search line, press enter to search, then on the next page select “Clear Apple Account balance”. On the next page select a chat or telephone call option.
Alternatively give Apple a phone call. Find a list of telephone numbers at: Contact Apple Support - Apple Support
When asking about this because you are changing regions, take a look at this article:
Change your Apple Account country or region - Apple Support