help in prime31 Etcetera android plugin

Hello....Please tell me which function I have to call in" EtceteraAndroidEventListener.cs" when user click "Not now" button for this--- EtceteraAndroid.showAlert( "Purchase Failed", "Do you want to retry", "Yes", "Not Now" ); --- I am calling this for "yes" button ----void alertButtonClickedEvent( string positiveButton )...thanks in advance