Missing api_key/current key with Google Services 3.0.0
Generate new config file (google-services.json) from: https://developers.google.com/cloud-messaging/android/client#get-config
Newly config file with "api_key": [ { "current_key": XXX } ] in client section
Update: or manually enabled service in developer console and generate key.
Adding empty current key value in google-services.json file solved this problem for me
"api_key": [{ "current_key": "" }]
Yes, as for the first time using with Firebase, i face like that.Click on your app menu and click "Manage".
you can download google-services.json again.
