I have an API in Google Endpoints, and I've generated the API key needed by the Android App I'm working on to access the API. However I have no idea where to supply the API Key when using generated clients library. Every request made from the app returns a 403, Android app is forbidden. I've read also in SO that it should be given in the header, but the closest that the Google Endpoints API docs mentioned is that an API key should be part of the URL, which however doesn't seem to be case if the request is from an Android client.
When the API key is removed from the API, any query, even curl, is able to retrieve the expected result. Any documentation on how this should be done with code examples will also be very much appreciated.
Edit: I am also wondering if Google itself has placed restrictions on using the android debug.keystore's SHA-1 in Endpoints.
Ps: my earlier question regarding this was unfairly down voted and the only answer received was about country restrictions, which I am sure has nothing to do with this. So maybe this time I'll rephrase my question in another way.