Starting August 27th at 10am PT (1pm EST) to August 29th at the same hour, the Alpha test for Call of Duty: Vanguard's new Champion Hill multiplayer game mode will be available to all PS4 and PS5 players. The Alpha is exclusive to the Sony ecosystem, but does not require any purchase - no pre-order, not even a PS Plus subscription (unless you live in Germany because of some German law or whatever).
You can pre-load the game itself on the PlayStation Store to be all set for tomorrow's release. more details can also be found on the Call of Duty official site. Call of Duty: Vanguard with its full campaign and multiplayer promising 20 launch maps releases November 5th for PS4/PS5, Xbox One/Series X|S, and PC.