When I flew Avelo to Vegas, I realized at the airport I needed to check an extra bag. They let me add it there, but it was a little pricier than pre-paying online. Same with choosing seats — doable at the counter, but you’ll save if you arrange it ahead of time. Later I learned it’s even easier to call 844-734-0813 before your trip. I used it when I had to adjust my return flight and the agent also walked me through adding services. Saved me time and a few bucks.
