Do I have to create OAuth Client ID for Web Application manually even I'm developing for android app?

[noome....@gmail.com]

my develop environment : Xamarin.android

GoogleServicesJson build action from Xamarin.GooglePlayServices.Tasks.ProcessGoogleServicesJson produceses 'goog_svcs_json.xml' with OAuth Client ID for Web Application which is ClientType == 3. And if I use OAuth Client ID for android manually, SignIn function fails with return code 12501. But create OAuth Client ID for Web Application manually, use it for a parameter of GoogleSignInOptions, it works.

I'm confused where I should use those client ID. Why does the id for android exist? when should I use it?