Not a problem, I feel bad now for having asked. My confusion was actually more from that being fairly common app now in America (CashApp, VenMo, PayPal, etc.) and so wasn't sure if you were describing something unusual from my perspective or simply weren't aware or...
In any case, it's mostly fine to use "cash" to mean "any form of cash", although I guess this case in particular was just barely ambiguous enough for me to be confused.
