Originally Posted by willywilkes

You are correct that it will check you in 36 hours before your flight, at which point your boarding position will be assigned. Starting 24 hours before your flight you can "check in" online or in the app to view, print, or receive a mobile boarding pass. You still select the option to check-in but you are technically checked in already, just go through with entering your confirmation # and name and it will then give you your boarding position and options for your boarding pass.

You can also choose to receive your boarding pass when you arrive to the airport - if you are not checking bags there may be kiosks that allow you to print your pass, otherwise you will see one of the agents at the check-in desk and they can print.