Ngnix Configuration that works when you have a server running at some port

webapp.conf

server {
        listen 80;
        server_name <your server name>;
        return 301 https://$host$request_uri;
}
        server {
        listen 443 ssl;
        server_name <your server name>;

        ssl_certificate /etc/letsencrypt/live/<your website name>/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/<your website name>/privkey.pem;
        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
        ssl_session_timeout 1d;
        ssl_session_cache shared:SSL:50m;

        location / {
        proxy_set_header X-Real-IP $remote_addr; # to get the real IP not the proxy one
        proxy_set_header HOST $http_host;  # This config is making it so that the Host header that the client sent nginx is sent on to the backend 
        proxy_set_header X-NginX-Proxy true;  # just a marker, saying Nginx proxy is used. Not really useful
        proxy_pass http://localhost:<your port>; # where you want it to forward the request to
        proxy_http_version 1.1; # set HTTP version
        proxy_set_header Upgrade $http_upgrade;   # For Websocket
        proxy_set_header Connection "upgrade"; # For Websocket
        proxy_redirect off; # For Websocket
        }
}