After loading into the Main Lobby, hover your mouse over the Play Apex tile in the lower-left corner of the screen, and left-click on it to view the other options

Hover your mouse over the tiny Trophy and Podium icon on top-right corner of the screen, and click on it to bring up the Tournament Match Create & Join screen. Note: you must not have any other Players in your Main Lobby to properly join a Tournament Match

Enter your Create (Admin) or Join (Participant) code in the proper alphanumeric text field on the screen, and hit Enter

After loading into the Tournament Match Lobby as a Participant, you can now:
a. Join one of the twenty teams or Observer team by right-clicking on the team name above the empty
slots (unless self-assignment is restricted by the Admin)
b. Edit one of the twenty team names by left-clicking twice on the team name text field (unless selfassignment is restricted by the Admin)
c. Use the text-chat feature (unless text-chat is restricted by the Admin)
d. Check the Match Summary
e. Ready up – this simply shows a green icon next to the Participant’s name to signal that they are ready for the Match to be started