@sharonyue to remove the panel you have to edit the template.
I do not know exactly where it is but it should something with topic template.
hello! i'm noob NodeBB user i installed script correctly and was searching for decent NodeBB template but few days ago after php version update i got error like this http://www.asysteo.pl and i really dont have idea what happend. I checked all instalation readme files and I even installed NodeBB again still no success.
What error do you see on the server? NodeBB has crashed, hence you see the 502 error served by nginx.