sudo apt install nm-connection-editor
This app is useful, on the L5 just as on any Linux computer. It allows you, as the name suggests, to create any kind of advanced connection, such as shared ethernet, VPN, etc.
The VPN connection settings UI allows you to set up VPN service even when your VPN provider doesn’t have a graphical client that runs on the L5. (Unless you prefer to do all that in the terminal.)