HybridAuth Client for Elgg

I've been trying to add the Google Client ID and Client Secret to the plugin to no avail.  Even though I input the following text exactly as laid out in the project page (e.g. http://SITE-URL/hybridauth/endpoint?hauth.done=Google) with my website URL (e.g. an https site), I get the following Google error message with the details:

Error:  401. That's an error...  Error: invalid_client.... The OAuth client was not found.


Again, I followed the instructions as laid out for "Setting up Google"  I also tried to replace the Authentication URL info laid out in the project page instructions with the one laid out in the actual plugin settings, which read:  Authentication URL:https://my-website.com/hybridauth/authenticate?provider=$providerId (e.g. which looks different from the project page URL text, so I'm confused about that too) Thanks for any help.