I get a syntax error in Gnome 3.36

[gearhead]

I cloned and made according to the instructions applied the bugfix for error #8 and Gnome will not enable the extension. The error is:

gnome-shell[837]: JS ERROR: Extension gnome-extension-connman@jaakko.hannikainen.intel.com: SyntaxError: missing ( after for @ /home/me/.local/share/gnome-shell/extensions/gnome-extension-connman@jaakko.hannikainen.intel.com/applet.js:231

The line in the file is:
for each(let [path, properties] in services)

I know nothing about javascript and am wondering how to get this working...

There are a lot more lines with this same structure and I am guessing this syntax is throwing off Gnome as the code base is pretty old... Any idea how to get this further? I'd like to have network indicator with connman/iwd in gnome.