Google Maps not displaying

I have a problem with the Google Maps not showing on a site that's been moved from staging > live. I get a Javascript error where the maps don't display.

JQMIGRATE: Migrate is installed, version 1.4.1
https://api.getsidekick.com/signals/v1/user/access-token Failed to load resource: the server responded with a status of 404 (Not Found)
maps.google.com/maps/api/js?v=3&libraries=panoramio&sensor=false&callback=agmInitialize:37 Google Maps API error: MissingKeyMapError https://developers.google.com/maps/documentation/javascript/error-messages#missing-key-map-error_.kb @ maps.google.com/maps/api/js?v=3&libraries=panoramio&sensor=false&callback=agmInitialize:37
maps.google.com/maps-api-v3/api/js/26/15/util.js:210 Google Maps API warning: NoApiKeys https://developers.google.com/maps/documentation/javascript/error-messages#no-api-keysTA.j @ maps.google.com/maps-api-v3/api/js/26/15/util.js:210
maps.google.com/maps-api-v3/api/js/26/15/util.js:210 Google Maps API warning: SensorNotRequired https://developers.google.com/maps/

I've added the Dashboard plugin to the site and activated it, but it isn't recognised. Currently I'm viewing the site via a modified HOSTS file with the URL set to the correct IP.

What can I do to resolve the problem?