There is probably some misconfiguration somewhere. In order to help you, could you please share with us a screenshot of the wp store locator settings screen, specifically what happens when you click the “Show response” button (see screenshot for reference).
This usually gives a good indicator on what is going wrong.
If you don’t want to share those details publicly, you can open a support ticket directly with us.
I checked the support ticket you later opened through the wpstorelocator.co website itself, and your issue seem to have been a combination of a misconfigured API key in the Google API Console and SSL certificate. Neither of which has anything todo with the functionality of the plugin itself.