OkAuthActivity - Unable to find

[vanjavanjavanja]

I'm getting:
Unable to find explicit activity class {com.github.gorbin.asnetutorial/ru.ok.android.sdk.OkAuthActivity}; have you declared this activity in your AndroidManifest.xml
on socialNetwork.requestLogin(); after I've added OkSociakNetwork as done with all other (working just perfect) options:

OkSocialNetwork okNetwork = new OkSocialNetwork(this, OK_APP_ID, OK_PUBLIC_KEY, OK_SECRET_KEY, OK_SCOPES);
            mSocialNetworkManager.addSocialNetwork(okNetwork);