Education Videos

No youtube playlist videos to be found - maybe API key not set ? This is the feed - https://www.googleapis.com/youtube/v3/playlistItems?part=snippet&playlistId=PL-cA97oQjuy-rgC5LZ5IY4wkw0YMhzJxy&key=AIzaSyCtrnD7ll8wyyro5f1LitPggaSKvYFIvU4&maxResults=50
The request cannot be completed because you have exceeded your quota.