Installed Flarum on Debian 11 with Apache. I can see the homepage when I navigate to the URL where I installed the forum. However beyond that nothing else works. Clicking even on my own admin "Profile" returns "The requested resource was not found."
Enabling debug mode shows:
GET <domain>/forum/api/posts
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL was not found on this server.</p>
<hr>
<address>Apache/2.4.54 (Debian) Server at <domain> Port 443</address>
</body></html>
