Currently we are doing a test-pilot of our forum and we wanted to limit the amount of people that can join.
We’ve configured openid and wanted to enable All new users must be explicitly invited by trusted users or staff. Public registration is disabled.
but doing so makes the login flow fail, when you are returned back from the OIDC provider it just tells you that you need an invite and that’s it.
On the video I set the forum to invite only and the forum to require everybody to login. I’ve also disabled local logins.
The only way to circumvent this is if you disable “invite only” and instead use “invite code”, if you do this, the first attempt to register will fail with an error about email being used, but if you re-enter the link with the invite, it will no longer ask you for the invite code and will let you finish the registration
let me know how can I provide more details 
im fairly new with discourse