Nginx default.cfg invalid parameter

Hi,

i am running nextcloud as a docker containter using unraid, i checked it’s log today and noticed this line

nginx: [emerg] invalid parameter “ssl,” in /config/nginx/site-confs/default:11

does it mean something is wrong with line 11 of the file?
here is line 11

listen 443 ssl http2;

thankful for any help.