The NetworkManager upstream project comes with a few commands which can be used to control and manage the NetworkManager service. This page gives a short overview of those commands which are available as part of the snap and what they are used for. Further details about their usage is given on linked pages.
The nmcli command offers a command-line based way to control and manage the NetworkManager service.
An explanatory description of the command and available options are available here
nmtui is the Network Manager Text User Interface. It is a curses-based application that allows easy configuration of connections and networking settings. Besides network-manager.nmtui, these other three commands are available:
More details can be found in the manual page.