並前往https://overcoder.net/q/3169341/%D0%BD%D0%B5%D1%80%D0%B0%D0%B7%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%BD%D1%8B%D0%B9-%D0%BA%D0%BB%D0%B0%D1%81%D1%81-myfirebasemessagingservice-android-studio