I am in big trouble because we migate user data into site after this i connect with OpenId Plugin . now after verification from the open ID provider it is coming back to discourse and asking to create username . now when click on username it is saying that this account is already there . what to do
Did you import only the users or also topics that you want the users to be connected to?
If it’s just the users, then maybe you should have just done nothing? But have a look at the debugging section of Discourse OpenID Connect.
I would expect things to be connected by the email address, so maybe something is different about the email addresses you imported somehow? Or maybe OIDC is expecting some external ID that you didn’t import?