Not able to load the load a sub domain in the machine - Sightless

I am using PWNbox and tried pinging the IP of Sightless. I was able to find a port that leaded to a webpage further when I tried it on my VM. I tried to use the functionality of the website which has a subdomain - sqlpad.sightless.htb . I am not able to access it, or it is implicitly inaccessible?

Is there a way to access it?

Did you add the subdomain to /etc/hosts file?

ie 10.129.xxx.xxx sightless.htb sqlpad.sightless.htb

In the pwnbox VM you have to use the following command:

echo “10.129.xxx.xxx sightless.htb sqlpad.sightless.htb” | sudo tee -a /etc/hosts