main function
Implementation
void main() async {
WidgetsFlutterBinding.ensureInitialized();
SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
// Fix for network request on old devices: "CERTIFICATE_VERIFY_FAILED"
ByteData data =
await PlatformAssetBundle().load('assets/ca/lets-encrypt-r3.pem');
SecurityContext.defaultContext
.setTrustedCertificatesBytes(data.buffer.asUint8List());
await Firebase.initializeApp();
runApp(App());
}