Can't configure Ubuntu with Whonix-Gateway


I have VirtualBox
I would like to make configuration Lubuntu instead of Whonix-Workstation with Whonix-Gateway.
I have used tutorial from your site Whonix-GNU/Linux-Workstation
I did:
sudo nano /etc/network/interfaces
then I put:
auto enp0s3
#iface enp0s3 inet dhcp
iface enp0s3 inet static

then from resolv.conf I have deleted everything and put:

Unfortunately it does not work. I have tried with Ubuntu/Lubuntu/Xubuntu. In Xubuntu nameserver changes every restart to default. In Lubuntu after restart everything stays the same as I have edit it but I have no internet connection. Whonix Gateway is running but my Linux Lubuntu is not working.
I have also tried this tutorial from github for Xubuntu but it does not work for me

I would be thankful for any help

Maybe a stupid question, but did you make sure that the Lubuntu VM is using the Whonix network?
Did you first test if a Whonix-Workstation works with your Whonix-Gateway? Is the Whonix-Gateway working correctly? Be aware that on first boot Tor must be activated on the Whonix-Gateway (you have a few settings messages that you must go through in order for the Gateway to work).
Also, did you make sure that on the Lubuntu VM the Whonix network is enp0s3? What does the command ip a return on the Lubuntu VM?