1
To add the Google Identity Provider to your application, you need to register your application with IAM server,
for this you need clientId and clientSecret of Google oauth application.Above call will return the id of the identity provider created along with the callback url.
You can get the clientId and clientSecret from the Google API
Console.
or follow these steps
2
You can then use the above callback url and add it to 
Authorized redirect uris in the Google API Console.