Saml via authentik - 405 Method Not Allowed

Hey,

im trying to set xibo (docker) to auth via saml again authentik as IDP, here my config:

<?php

# If you need to add custom configuration settings to the CMS settings.php file,
# this is the place to do it.

# For example, if you want to configure SAML authentication, you can add the
# required configuration here

#$authentication = new \Xibo\Middleware\SAMLAuthentication();
$samlSettings = array (
   'workflow' => array(
        // Enable/Disable Just-In-Time provisioning
        'jit' => true,
        // Attribute to identify the user 
        'field_to_identify' => 'UserName',   // Alternatives: UserID, UserName or email
        // Default libraryQuota assigned to the created user by JIT
        'libraryQuota' => 1000,
        // Initial User Group
        'group' => 'Users',
        // Home Page
        'homePage' => 'icondashboard.view',
        // Enable/Disable Single Logout
        'slo' => true,
        // Attribute mapping between XIBO-CMS and the IdP
        'mapping' => array (
            'UserID' => '',
            'usertypeid' => '',
            'UserName' => 'uid',
            'email' => 'mail',
        )
    ),
   // Settings for the PHP-SAML toolkit. 
   // See documentation: https://github.com/onelogin/php-samlsettings 
   'strict' => false,
   'debug' => true,
   'idp' => array (
            'entityId' => 'https://auth.example.services/application/saml/xibo/sso/binding/init/',
            'singleSignOnService' => array (
                'url' => 'https://auth.example.services/application/saml/xibo/sso/binding/redirect/',
            ),
            'singleLogoutService' => array (
                'url' => 'https://auth.example.services/application/saml/xibo/slo/binding/redirect/',
            ),
            'x509cert' => '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',
        ),
   'sp' => array (
        'entityId' => 'http://xibo.example.de/saml/metadata',
        'assertionConsumerService' => array (
            'url' => 'http://xibo.example.de/saml/acs',
        ),
        'singleLogoutService' => array (
            'url' => 'http://xibo.example.de/saml/sls',
        ),
        'NameIDFormat' => 'urn:oasis:names:tc:SAML:2.0:nameid-format:emailAddress',
        'x509cert' => '',
        'privateKey' > '',
    ),
    'security' => array (
        'nameIdEncrypted' => false,
        'authnRequestsSigned' => false,
        'logoutRequestSigned' => false,
        'logoutResponseSigned' => false,
        'signMetadata' => false,
        'wantMessagesSigned' => false,
        'wantAssertionsSigned' => false,
        'wantAssertionsEncrypted' => false,
        'wantNameIdEncrypted' => false,
    )
);

?>


but after succesfull login i got this:

and console brings me this:

does anyone got it work?