Linphone xamarin forms android

i am developing my voip app with xamarin forms using linphone sdks. i managed to run and publish the application to install but i have problems with android. the application works but how can I receive notifications? I created a service that keeps me the client registration always active but when I restart the phone I need to initialize the app at least once otherwise it doesn't work. the service works because i put a test notification, but the system does not communicate with linphone sdk.
i just need someone to solve this problem for me then i keep developing it myself