@abhinov-singh If you are using Nginx on Ubuntu, the configuration files or symlinks (including ports, etc.) are at /etc/nginx/sites-enabled/
See also which ports are left open by your firewalls (server, PC).
While trying to install nodebb on Heroku i am having problems to connect to postgres databases provided by Heroku add-ons - "Standard 0" and up. Connecting to lower performance Heroku postgres add-ons, like "Hobby dev" and "Hobby basic", works.
Thank you very much @PitaJ . now it is ok. but i remember that i had same problem two days ago after configure ngnix and config. site was good also i entered some categories and soon suddenly i got above errors. i hope it wont give error again.