I have configured router [added a virtual server] enter image description here

Apache service is running...

● apache2.service - The Apache HTTP Server
 Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
 Active: active (running) since Tue <not important>; 1h 21min ago
   Docs: https://httpd.apache.org/docs/2.4/
Process: 14290 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)


  Main PID: 14294 (apache2)
      Tasks: 55 (limit: 9207)
     Memory: 7.3M
     CGroup: /system.slice/apache2.service
             ├─14294 /usr/sbin/apache2 -k start
             ├─14295 /usr/sbin/apache2 -k start
             └─14296 /usr/sbin/apache2 -k start

Jul 20 02:19:54 inspiron5567 systemd[1]: Starting The Apache HTTP Server...
Jul 20 02:19:54 inspiron5567 apachectl[14293]: AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using fd01::>
Jul 20 02:19:54 inspiron5567 systemd[1]: Started The Apache HTTP Server.

Firewall details-

Status: active

To                         Action      From
--                         ------      ----
Apache Full                ALLOW       Anywhere                  
Apache Full (v6)           ALLOW       Anywhere (v6) 

OS- Ubuntu

I know next to nothing about programming (just moved to Linux). so I might not have mentioned all details but I seriously want to learn so please help me out.