Weird... I already implemented GMaps, GooglePlay Games, IAB, AdMob, Analytics, Google Cloud Console (HTTPS config) <- most things in Android and the web.. Never had that trouble to get a working key
"\n"?
Edit: Replacing the new lines (\n) did not helped in my situation, but found a other solution.
Instructions (for dummies like me xD):
1. visit https://console.cloud.google.com/iam-admin/
2. create a new project.
3. search for translation api and activate.
4. create an api key (NOT a service - here are Google docs quite misleading I guess)
5. copy the key (it has approx. 50 chars and does not contain line-breaks)
6. in the workflow choose google as provider, setup your desired language
6. use this key for the workflow alfred ("tr-set api key")
7. never share your key
8. Profit!
Thanks rustycamper for this awesome workflow!