on some site i went on today it said pc could start the pre download for the beta today at 6pm bst take it this was duff info
The Beta isn't due to release for the PC until the 10th August and there has been no announcement about pre loading.
PC Early Access Multiplayer Beta: 10:00 AM PT, August 10, to 10:00 AM PT, August 11
PC Open Multiplayer Beta: 10:00 AM PT, August 11, to 10:00 AM PT, August 13
There will also be a Blackout Beta in September 2018. Note that Multiplayer Beta codes will also grant you access to the Blackout Beta, first on PS4