The 1-click installer is sort-of a standard install, but it keeps you from knowing the way that you’re supposed to do stuff.
You really need to follow the Discourse official Standard Installation. I think, though, that you can ssh (or use the console) to access your server as you have done already and
cd /var/discourse
./discourse-setup
If that works, then you can say you have an “official install” and you’ll know that stuff like ./launcher rebuild app will work.