In N-OC there is the Fleet tracker function. Where you can get the real flight information from various sources like Google Maps, Flight Radar 24 or N-Tracker. For Google maps, you need to have a billing account at Google. However, a common problem with using this feature is that you are met by the message "For development purposes only" and we want to share here how to solve this.
What needs to be added to get it to work is that you need to get a new google key that you add to the setup parameter "GoogleMapsAPIKey" in N-OC:
You can read how to get it through this link: https://developers.google.com/maps/documentation/javascript/get-api-key
If you are still experiencing problems after this it can be that you must activate the new Key. Which you can read more about here: https://developers.google.com/maps/documentation/javascript/error-messages#api-not-activated-map-error.
And as always, reach out if there are any questions, but this is a short start guide on how to solve it in the first place when you are met by this message.