Have to be honest I struggle with understanding exactly what that code is doing - I am not good with scripting. Where do you even enter that?
However, I took a guess that it means, “make a very simple connection file with just the basics”. So I made:
[wifi]
ssid=my-wifi
[wifi-security]
key-mgmt=wpa-psk
psk=*secret password*
and chmod 600.
And that still doesn’t work. The file is ignored and nm-applet makes a new one, asking for the password.
So, where do I enter that code?