Start/stop GL-X750's wireguard client from shell

I would like to control the built-in wireguard client (which works great) from the shell. I’ve seen snippets of code but none seems to work
Is there a definative guide on how to connect/disconnect a pre-exisiting client?

/etc/init.d/wireguard stop

/etc/init.d/wireguard restart

This results in the following code containing

uci: Entry not found
Cannot find device "wg0"

the message means wireguard is not started.

Ok - This wireguard configuration works from the gui but it seems that this CLI approach doesn’t work… Is there another route?