Yes, you can conveniently buy your ticket or pass with a bankcard in the BudapestGO app, so you can validate your ticket on your mobile phone or present it to the ticket inspector in an environmentally friendly way.
If you still prefer to travel with a paper ticket, you can find out where the BKK sales points are located on the map in the BudapestGO app. In the travel planning settings, you can select the BKK sales points and resellers to be displayed on the map under the More button.