Beginning on July 1, 2021, Disney Guests that opt to use the Disney Magical Express will no longer be mailed confirmations. Instead, they will need to use either their Magic Bands or the MagicMobile App to check in at Orlando International Airport.
If a Guest does not have either, they will be checked in manually by using a Government issued ID.
As reported earlier here on DisneyDawgs.com, Disney will be discontinuing the Magical Express in 2022. You can read that post here