We have configured an auth provider using open id connect and created registration handler to create and update user. I have a requirement to get the ID Token as well. so I tried to use String token = Auth.AuthToken.getAccessToken(authproviderId, 'Open ID connect') where authproviderId is the ID of the provider that I configured. This token value always returns null. Can anyone help me with this issue? Appreciate your response. Thanks!

User Object has Records and Custom Object[Emp] has no records in it. User object has records in it, so we can't create a master detail relation.Created lookup relation, Then try to convert look up to master by clicking on change field type there is no master detail option to select.
emp Object has below fields.