Instructions for Ubuntu 17.04

Right-click on the desktop and select "Open Terminal" from the context menu.
In the window type the command:
sudo apt-get install network-manager-openvpn

After the command you will need to enter your user password. Perhaps OpenVPN package will already be installed on the system:

Now type the following command:
sudo apt-get install network-manager-openvpn-gnome
wait until the installation is complete:

Now go to the billing panel and download the configuration file, or create such a file and copy the content from the text field in the billing.

Create a new vpnconfig directory in your home directory and transfer the downloaded configuration file there. You can do this with any file manager. For example, default Nautilus.

Then click on the Network Manager icon and select "Edit Connections" from the menu:

In the window click the "Add" button, then in the drop-down list select "Import a saved VPN settings" and click "Create":

Select your configuration file and click "Open”. Click "Save" button in connection properties window:

Connection created. Now you can close the window with a list of connections, click on the icon "Network Manager" and select your VPN:

Connection OK:

Now use some service to determine your IP address. For example, here. It must differ before and after connection.

Our congratulations, everything is ok and operates properly.