OK - this one is extremely basic - and hopefully solved in an instant!
I've never managed to use "Samsung Pass" because essentially it never accepts my password to login, even after I have changed it, and written it down, and there is zero chance of my getting wrong. And then waiting 20 minutes, 1 hour, 3 hours for it to "propagate" through whatever servers Samsung uses to hold all this user data.
So I just have a brand new Galaxy S21. And its doing exactly the same as all other previous Galaxy phones (e.g. S9+, and S9 before that...) - Samsung Pass is a hopeless failure.
And that's a pity because it looks like it has some great features! And I would really like to try them...