Sein I'll just shamelessly plug one of my previous post regarding how to install Gnome Extensions: https://discuss.getsol.us/d/2689-my-top-ten-must-have-gnome-extensions
That post was from last year though, so I do have to edit that in step #2 Gnome Tweaks no longer has an option to managed extensions. (Gnome Tweaks is still useful to keep around though). Instead with Gnome 3.36 there is an "Extensions" application that the Gnome developers created for this release, which works in much the same way as it did in Gnome Tweaks, just an extra application for it.
I had tested many extensions since 3.36 was released, and I have tested the top bar extension you speak of and it does indeed work with the Solus Gnome 3.36. Solus has a few extensions in the Software Center because 1.) they deem them for essential use i.e. TopIcons Plus allowing tray icons, 2.) Solus can guarantee support with the extensions they do ship in the SC to work with the latest Gnome, and 3.) There may be something I'm forgetting, but if so hopefully someone else could correct me, but other than that I hope we've been of some help here and enjoy using Gnome!
