luceos Capp do you mean the installer when you install Flarum? This probably means Flarum is not installed in the right directory or your rewrites for Nginx aren't set up. Check the documentation to understand how to achieve that last point.
luceos Capp okay and where did you find that link, because that article can be found here: https://docs.flarum.org/install
RelicSystem luceos okay and where did you find that link It took a while to find the elusive link but I suspect it came from this post https://discuss.flarum.org/d/21101-demos-come-to-flarum which was linked by @SychO in the beta 2.0.0 post here https://discuss.flarum.org/d/32901-staff-diary-v20-cycle/316