It is possible to vote while outside the country by going to designated embassies but if you live outside of the country or are further away than 500km from your legal residence the day of the vote you are not obligated to vote. Also, a lot of people (above 20% on the last election) that should vote don’t despite it being mandatory since that law is pretty much never enforced in practice. Source: I’m Argentinean.
Did the pope vote in Argentina's election?
Can he? In general, can/do popes vote in their home countries?