Haha, I used to have the same problem! It’s very annoying that it’s pretty bad documented and you keep being referred to the Tappy Chicken example.
On EventBeginPlay >
If > Is Logged In (GetPlayerController)
True >
False > Show External Login UI (GetPlayerController)
That is actually all you need to get the login screen popped up.
You could also try to add a UI button that does this.
OnReleased >
If > Is Logged In (GetPlayerController)
True >
False > Show External Login UI (GetPlayerController)
Small side node:
Don’t forget to invite yourself to your beta, your dev-account is not automatically alpha/beta participant.
For myself, I’ve 2 google accounts. 1 for access to dev console, 1 i actually use on my phone and use for alpha/beta testing.