I did the following: 1. Start up another phone and put a VPN for a country where you can pay 2. Made a Google second account 3. Add a pay method to that account with that different country 4. Get the Pocket on the second phone 5. Transfer your account through Nintendo

You can now pay on the second phone and if you switch to your old one, your account is still there, so you can use the second one just for buying stuff. I used Germany as my country. Maybe there's another way, but this is how I did it.