@hummina. Thanks for posting.
From the error message that Joomla lists, it seems that the path ‘docs/publicdocs’ does not exist. One thing to keep in mind is that web servers are typically case-sensitive. So, for example, if the folders are actually named “Doc” and “PublicDocs”, then specifying “doc/publicdocs” will not work. You will have to specify “Doc/PublicDocs”. This actually happened to another user of the plugin.
Now, make sure that your docs folder is in the root of the Joomla installation. If you are still having trouble, please post a link to the webpage.