Docman plugin not work

I installed the plugin, enabled it and entered the key.
The plugin does not see docman categories.
I tried uninstalling and reinstalling the plugin but it doesn't work.
I followed the tutorials and documentation
Joomla 4.3.4 

Please help me

Please share the login credentials of the back end site with "Super User" access and FTP so that we can check and give you a better solution. Thanks