A SAML assertion contains information about a user in the form of a series of attributes. These user attributes in the SAML response can be mapped in the configured Service provider.
NameID is the unique identifier for a user in the SAML response. By default, module sends email in the NameID attribute of the SAML response. You can also configure the NameID attribute to Drupal Username, if required.
In case, you need any other custom Drupal attribute as a unique identifier to be sent as the NameID in the SAML Response, reach out to us at email@example.com.
If any additional user information like Email Address, Username or User Roles is to be sent in the SAML response you can achieve this by using the User Attribute feature.
If you want to map any additional user attributes, you can do so using the Additional User Attributes field. These attributes will be sent in the SAML assertion.