A unique identifier (ID) value should be configured for OIDC, OAuth2,
LDAP and SAML authentication method types and is usually a value such
as the email, username, or upn for example.
Whenever a user logs in with a token, these authentication types issue
a "sub claim" that contains details uniquely identifying that user.
This sub claim includes a key containing the ID value that you
configured, and is used to distinguish between different users from
within the same organization.