I’m currently stuck on the same issue as @rishabhchand007 had, the 403. A fix for this on Plesk is allowing directory discovery on the server, however, this will not do much since your new error will be 404 (on upload/<some_file>). The rest of the panel works perfectly fine, I’m even able to upload a new site logo. Just when I try to access the media library, or when I try to add new media, it will throw an error. @Arklogic since you managed to set this up, do you maybe have a guide for us which you followed? 
If any of you could help me, that would be really appreciated! 