Google Maps MissingKeyMapError NoApiKeys

Using v3.6 after a transfer to a different domain the map is first loading and then this message shows up:

Oops! Something went wrong.
This page didn’t load Google Maps correctly. See the JavaScript console for technical details.

I have updated the links which are called like this in WP:

[map kml=”http://NEWDOMAIN/wp-content/uploads/2012/map.kml” maptype=terrain style=”width:100%; height:340px; border:1px solid gray;”]

The following errors are showed in console:

“Google Maps API error: MissingKeyMapError https://developers.google.com/maps/documentation/javascript/error-messages#missing-key-map-error”js:34:391
“Google Maps API warning: NoApiKeys https://developers.google.com/maps/documentation/javascript/error-messages#no-api-keys”util.js:210:12
“Google Maps API warning: SensorNotRequired https://developers.google.com/maps/documentation/javascript/error-messages#sensor-not-required”

I can’t remember if there was an API key and I can’t also find one in the current plugin setting or elsewhere. Appreciate any advise to solve this.

https://ww.wp.xz.cn/plugins/google-maps-gpx-viewer/