It looks phpBB 3.2 is no longer super friendly with Nginx unless you put a specific entry in your server block…And by not super friendly…I mean you can’t even install the damn thing anymore with a standard server block configuration!

However, All you have to do is add this after one of the locations in there:

        location /install/app.php {
                 try_files $uri $uri/ /install/app.php?$query_string;
        }

This took me a while to find, so hopefully it helps you! After adding this, I finally was able to get the Installation to appear after clicking the “Install” tab 🙂

Found it here:

https://www.phpbb.com/community/viewtopic.php?t=2405881

Thanks battye!