I want to login vBulletin through my site

[userform3]

Hi,

from a CMS the user should log in to the vb.
The login procedure takes place in CMS.

At vb I got this https://www.vbulletin.com/forum/blog...n-your-website link sent to me by the users.
For the purpose of the login I created a plugin, registered in vb Backen.
The plugin itself is stored in

/var/www/dieseite2_de/html/forum/core/packages/dieseite2/api/dieseite2.php

When opening the forum via the URL www.test.dieseite.de/forum/ I get the following message:

Couldn't read config file config.php.

The error message is generated in the file

/var/www/dieseite2_de/html/forum/includes/vb5/config.php

What am I doing wrong?
Has the plugin been stored in the wrong place?

Anyone have any idea how to solve this?
What am I doing wrong?
Has the plugin been stored in the wrong place?

Anyone have any idea how to solve this?

regards
user