Depends on a few things. Do you have a valid visa? If yes, you don't need a onward ticket as immigration won't ask and you can show your visa to the airline.
If you plan to enter as a tourist on visa exempt, then you must have a onward ticket else the airline would most likely deny you boarding and the immigration officer could deny you as well (not super likely, but possible).
Guys, the author here is conducting a study, not promoting cashless payments. Just answer the questionaire in a way that reflects your opinion to show that foreigners do not want to pay with QR then.