azure musk
Using the MuMu emulator to purchase top-ups is as of currently posting bugged. It seems to be a conflict with the emulator with the payment processing with the game.
In my circumstance, I could not use Google Pay, so I tried using my card directly. This caused Xsolla (their other processor) to charge me without a receipt. The game did not update for the purchase either. If you are currently dealing with this problem, I highly recommend contacting Xsolla Support to get a status for a refund or acknowledgment the purchase is being reversed.
If you're still feeling a need do Top-Ups, you should download the game through your phone for purchases. It is the safest method.