For regular non-rev, the departure tax is part of what you are charged. For jumpseat, you’ll need to be proactive at the departure gate and pay it there. J/S is the least expensive way to get out.
The United app won’t display a boarding/standby pass, so you’ll need to check in at the ticket counter to show your passport and will be issued a paper version, which will get you through security.
Next, go to the boarding gate and let the agent know you need to pay your exit fee (should be $30ish, depending on the exchange rate). If I remember correctly, it must be paid with a credit card.
Buen viaje!
Last edited by BJXFlyer; 11-18-2019 at 04:06 AM.