Hey,
May I ask how you got rid of the “WARNING: expected origin…” issue?
I’m having the same issue so I can’t make authentication work…
As far as I understand, the warning triggers if the identityProvider URL isn’t the same URL as the event from which it is triggered? 
That can’t be right, because the Internet Identity URL isn’t the same as my app.
Any help would be appreciated 
P.S: I’ve tried with both http://127.0.0.1:4943/?canisterId=canisterId and http://canisterId.localhost:4943/ syntax and Chrome, Firefox and Safari.