@Fallen Angelic copying my gssr guide from other thread.
"STEPS TO GSSR-
1.**Make google account full JP region using a fake jp credit card generator, must use JP zip code and name in kana/kanji.
When you input the info it will return an error. Don't mind it, close google play and open it. Your account will be full JP, it MUST say your region is 日本 in location. Just for safety I stay on VPN any time I use the account.
2. Wait 1 full day.
3. Add your paypal, if get or-cac-01 error or other error wait 3-4 more hours and try again.
4. PP is attached and you can buy like normal....(for now) so long as google doesn't somehow block this method.
**make sure the account you turn full JP region locked does not have any EN games you make purchase on you will no longer be able to."
I should also note I'm sure everyone knows but just in case, you must have installed FGO from the account you want to use.