SAML attribute mapping First Name, Last Name available?

[oknak]

Installation info:
Xibo Version 4.3.0 / Docker on Ubuntu 24 VM

SAML integration is enabled via settings-custom.php

User Login via IDP is working well and users are created if they login first time.

UserName and email are handed over by idp to xibo-cms and are visible in the user profile.

The issue:

First Name and Last Name are no used by xibo-cms alltough it is provided by idp.

My mapping settings in settings-custom.php looks like this:

    'mapping' => array (
        'UserID' => '',
        'usertypeid' => '',
        'FirstName' => 'urn:oid:2.5.4.42',
        'LastName' => 'urn:oid:2.5.4.4',
        'UserName' => 'urn:oid:0.9.2342.19200300.100.1.1',
        'email' => 'urn:oid:1.2.840.113549.1.9.1')

I’m not sure about the xibo attribute names ‘FirstName’ & ‘LastName’ because it is nowhere decribed. At least I couldn`t find it. I tried also ‘firstName’ & ‘lastName’ but no success.

Does anyone know the correct attributes. Is this supposed to work at all??
Thankful for any support.