Google Cloud Endpoint scope usage

[Canemacchina via StackOverflow]

according to Google cloud endpoint documentation, in @Api annotation (or @ApiMethod), we can use a "scope" parameter, that is:

If not supplied, the default is the email scope (https://www.googleapis.com/auth/userinfo.email), which is required for OAuth. You can override this to specify more OAuth 2.0 scopes if you wish. However, if you do define more than one scope, note that the scope check will pass if the token is minted for any of the specified scopes. To override the scopes specified here for a particular API method, specify different scopes in the @ApiMethod annotation.

Reading this docs seems that we can ask, for example, for drive scopes. In fact, if we put here https://www.googleapis.com/auth/drive.file, the endpoint will ask the user for the drive auth. But, how can I get the valid token to make a call to the google api? I mean, this scope parameter is intended only for login purpose, or I can use it to obtain Oauth2 tokens to call Google Apis?

I think is only for login purpose (just because I haven't found something about using endpoint to connect to google api) but I need a confirmation.

Thanks in advance

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