How to send location updates to server and check for a response in the background in Xamarin.Forms?

My application needs to get location updates while the app is in the background. It then needs to send the location to a server and wait for a response on whether to create a local notification or not. I am assuming this must be done in native code for both iOS and Android but I do not know how to go about doing that. Any help would be appreciated. Thank You.