From a store you should get a code you can enter on www.callofduty.com/wwii/beta
Some online stores will mail the code quick other later on.
In Xbox or ps store. Your account is registered for the beta
Ok cool cause I bought mine on the ps store and didn't get a code or anything. So sounds like I won't need one then since I did use the ps store.
Than you don need one.
beta date's are
ps4 25 aug - 28 aug
ps4 and xbox 1 sep - 4 sep