In Italy you pick up the ticket at the toll gate when you enter the ramp, and based on the same ticket you pay the toll at the exit toll. The toll is based on distance travelled. They basically work like a parking lot.
If you are going from Zurich via Studerno the only toll portion in Italy is from Bolzano Sud to Chiusa and the toll is €2.60. If you go via Innsbruck (Brenner Pass) the toll portion in Italy is from Vipiteno to Chiusa and the toll is €4.10.
For those amounts I wouldn’t bother to use cards. If the toll station is unmanned the cash machine gives change, but the above are the amounts you will pay, so that you know, in case you want to use the exact change. If you want a live human toll taker, choose the toll gate with white sign displaying a black hand holding cash. The one with white sign displaying cash (but no black hand), in an automatic cash machine. You can also use cards at the cash machine, but the toll gate manned by a human (black hand on white sign) takes only cash.