How to do it ?
Steps I am following
(a) Reading from here https://docs.nodebb.org/configuring/proxies/apache/
(b) Making subdomain.conf , keeping it inside /etc/apache2/conf.d/includes
and attaching this line Include /etc/apache2/conf.d/includes/subdomain.conf into httpd.conf
(c) Changing URL of config.json inside NodeBB folder to http://subdomain.conf
Code which I am using in subdomain.conf is as follows :
RequestHeader set X-Forwarded-Proto "http"