I had only received the access code for the PC platform, but since I don't have a PC, I wanted to play on my PS5. I saw that many people are going through something similar.
Here’s what I did: the email linked to this EA account is an "old" one that I didn’t really use anymore. In fact, I currently use a different email on my PS5. When I received the email with access to the PC version, it was sent directly to my current email (the one I use on PS5).
After several days trying to contact EA and spending many hours reading through this forum, I decided to log into that old email to see if anything about the playtesting had been sent there. To my surprise, there were two emails waiting: one with the access code for PS4/PS5 and another for Xbox.
Note: these codes were sent on the same day I received the PC access, lol.
So, make sure to check the inboxes of all the email addresses you've ever used with EA, as the access codes might have been sent to different ones.
Hope this helps!