That's the shortcut to actually getting the Fire key we have to insert in the switch, usually next to the button panel, that kinda looks like an ignition in a car. Says, OFF, ON, FIRE(in red)

As a FireF, elevators require quick access to floors for emergency personnel. Hitting the floor and close simultaneous works, but many close buttons don't work or aren't there. Method 2 is simply holding the floor number down from the moment selected until you arrive at the floor

FYI, they got it wrong, as a FF, I know the trick. You enter elevator and press your floor and don't let go of the button. Required on all elevators. Works 100%