Is it necessary to take possession of the money at the sitting when charging someone's PUBG game balance? And what is the ruling on selling Google Play gift cards that contain a monetary balance in dollars for purchases only through Google?

Exchanging credit in games for compensation is considered selling a benefit, not a loan or currency exchange, therefore, immediate possession (tahabudh) is not required. As for prepaid cards used for purchasing from a specific website, their ruling is the same as the balance they carry and are considered currency exchange (musarafa). They require equality (tamathul) and immediate possession (taqabudh) when the currency types are the same. However, a difference in amount (tafadul) is permissible when the currency types differ, provided immediate possession (taqabudh) takes place.