When you are opening /install or public/install you are getting 404 page instead of installation [https://demo.froid.works/public/install or https://demo.froid.works/install]

But when you try opening using index.php in url https://demo.froid.works/public/index.php/install You get the installer

Solution: You are not able to access installer at /install because the mod_rewrite in not enabled on your server. Once mod_rewrite in enabled you can access directly https://demo.froid.works/public/install or https://demo.froid.works/install