As of today, the Panama Metro implements a new form of payment

The Panama Metro announced that from today the new payment method will be implemented for the benefit of the thousands of users who use this transport system daily, it is payment through Visa and Mastercard with a contactless card.
Users of the Panama Metro must bring their contactless credit card to one of the identified validators and they will be able to enter any of the stations and take the tour.
When you arrive at your destination station, you will again validate the trip with your card at the turnstiles, making your exit faster.
It should be noted that with this new payment alternative it is not necessary to insert the credit card, or enter security codes to validate the transaction