As you can see on that page the background on the map is telling you for dev purposes only which indicates you have not set up your Google Maps API correctly. You need to add your billing credentials. (using any browser inspect the page and it will show you the exact error message on that page.) That page also has a pop up from Google asking if you own that site, the answer is yes. With the WPSLP plugin you must maintain your own Google API keys
js?libraries=geometry&language=en®ion=US&key=AIzaSyBERGRs4HdtPIg2vLa7P2ZplcaM1mn1p7U&ver=5.5.8:64 You must enable Billing on the Google Cloud Project at https://console.cloud.google.com/project/_/billing/enable Learn more at https://developers.google.com/maps/gmp-get-started
_.Uc @ js?libraries=geometry&language=en®ion=US&key=AIzaSyBERGRs4HdtPIg2vLa7P2ZplcaM1mn1p7U&ver=5.5.8:64