To correctly use this plugin you need to know two things - Google Place ID and Google Places API key. These are two different values, please do not confuse them.
There is nothing complicated and the whole process will not take even 5 minutes,
and as a reward you receive a constantly updated and collected Google Rating and Reviews!
First of all, you need to find Google Place ID: this is the identification of your Google Place (business). It should be like that: ChIJ.., for instance: ChIJ3TH9CwFZwokRIvNO1SP0WLg. If you know it, go to How to create Google API key
Please keep in mind: your Google Place must have a physical address, because Google Place API, which is used in this plugin, works only with physical Google places, it's not possible to connect an area or virtual place. Unfortunately, it's a limitation of Google, not specifically the plugin.
The standard way to find your Google Place ID is to go to https://developers.google.com/places/place-id and search for your company name. But sometimes it just doesn’t work.