'Userinfo ID' not working or misunderstanding?

[PeteBo]

Hey,

i use latest Matomo and LoginOIDC plugin connected to my Keycloak.

For new users logging in first time i wish to use the OIDC attribute preferred_username and so i entered this into the Userinfo ID field of the plugin configuration.

But new users coming from Keycloak are still registered with email address as username.

my OIDC Userinfo and Token attributes appear to be correct. Here is a userinfo example:

{
  "sub": "********-ee02-4c0b-aa5b-############",
  "email_verified": true,
  "name": "Max Mustermann",
  "groups": [
    "offline_access",
    "default-roles-xyz-123456",
    "uma_authorization"
  ],
  "preferred_username": "max.mustermann",
  "given_name": "Max",
  "locale": "de",
  "family_name": "Mustermann",
  "email": "[email protected]"
}```

Any hints on how to set this up correctly?

Thanks & best regards,
Peter