The old way of configuring Debian-based network interfaces was based on the ifupdown package. The new default is called Netplan, and although it's not terribly difficult to use, it's drastically different. Netplan is sort of the interface used to configure the back-end dæmons that actually configure the interfaces. Right now, the back ends supported are NetworkManager and networkd.
If you tell Netplan to use NetworkManager, all interface configuration control is handed off to the GUI interface on the desktop. Th