Please help on error with GoogleMapsPlatformAPI -- getting 403 in trace session

When trying to access the below URL via ServiceCallout Policy in APIGEE,facing below error,

Please provide solution for the same.

https://maps.googleapis.com/maps/api/geocode/json?address=98101®ion=US&sensor=false

{

“error_message” : “You must use an API key to authenticate each request to Google Maps Platform APIs. For additional information, please refer to Google Maps Platform - 3D Mapping & Geospatial Analytics”,

“results” : ,

“status” : “REQUEST_DENIED”

}