Services is not defined

Thunderbird Add-ons
#1 
ChromeUtils.import("resource://gre/modules/Services.jsm");

I have this line of code and so does Owl for Exchange and it is creating errors saying “Services is not defined” in the Error console for both Owl for Exchange and my own addon.
What has changed and how can it be fixed? This is in TB 67.0b1
Blessings
Graeme

#2

There was a change to module imports, though I don’t know if it causes that error:
https://thunderbird-webextensions.readthedocs.io/en/latest/how-to/extensions68.html#javascript-module-imports

#3

reference Services is not defined in Beta