You must have a valid Google API key in order to access and import Google reviews.
To get one, visit the Google Cloud Platform Console.
Get the API key for the first time
Create a new project or select one that you previously created and then click on Sign up to get an API key.
You will be prompted with a message to enable billing for your project. This step is mandatory. If billing is not enabled, you will get an error message. Read more about this here.
After you fill out the needed information, Google will try to validate your card but they will not make any charges.
Learn more about these initial steps at: https://developers.google.com/maps/gmp-get-started
Once you set up your billing, another window will pop up with your Google API key.
You must have a valid Google API key to access and import Google reviews.
Use a previously generated API key
In case you already had your billing set up, go to APIs & Services > Credentials and there you will have your API key to copy from, or you can create one from there.
Use the API key in the Testimonial Importer
After successfully located or generated your API key, paste the key into the plugin’s settings. Got to Testimonials > Import > Google.
Enable ‘Maps Javascript API’ and ‘Places API’
Also make sure your project has the ‘Maps Javascript API’ and ‘Places API’ enabled, by going to ‘APIs & Services’ -> ‘Library’.
After that, type “Maps Javascript API” in the search box to quickly find it.
Once you locate it, click on the Enable button.
Do the same thing with the “Places API”.