Last time I posted how to get an invite for Hack the box, Now lets connect to it's VPN.
Log in to hack the box and on left hand side, you'll see the "Access" tab
Observe that the status is not connected
Download the .ovpn file
For accessing the vpn, go to the kali machine and install openvpn
For me it's already installed
Now type
openvpn --config filename
You'll get the status "initialization sequnce completed"
Also you can verify the status
Now you're connected and can access whatever machine you want
Happy Hunting.