https://www.gamespot.com/articles/call-of-duty-black-ops-4-ps4-multiplayer-beta-prel/1100-6460922/

Preloading for the Call of Duty: Black Ops 4 beta on PS4 has begun, which means that you can download it now and be ready to play when it starts later today. The multiplayer beta is private, so you'll need to have a code, which is obtained by pre-ordering at select retailers. The beta can be downloaded through the PlayStation Store and weighs in at 18.09 GB.

The Call of Duty: Black Ops 4 private multiplayer beta weekend starts on August 3 and will run through August 6. A second beta weekend will then happen on August 10 through August 13. While the first weekend is exclusive to PS4, the second one will be available on PS4, Xbox One, and PC. You can take a look at the full schedule below.