Custom callsign

Hello!

Unfortunately, you cannot make your callsign AC791 - custom callsigns, along with changeable usernames, were removed with the introduction of the 20.2 update.

However, based on your previous topic, I assume you want to set it to Air Canada - which you can do. Simply open Infinite Flight’s settings, go to the Online tab, tap your callsign, go to the Airlines tab and scroll down until you find Air Canada; then type 791 in the ID tab.

Or, you can do what Adam suggested above.