So that a user can log in to the Intrexx portal via the external ID provider, this user must also be registered as a user in the ID provider.
Users create accounts with social networks themselves. Users can also do this with some original ID providers.
But with some ID providers, you need to register the users yourself.
But regardless, the user must be registered both in Intrexx and the ID provider.
More detailed information about users in Intrexx is available in the following chapter:
Example - AzureAD
Normally, you have created the users in AzureAD. Typically, all users have access to Intrexx (application) in AzureAD by default.