It's possible to build app that to send notifications to nearby users in Xamarin.forms ?

Hi guy's
I developing app using xamarin.forms and i want to add service that allow user to send a notification to nearby users they have the same app , it's such as car booking apps , i was read about Google nearby notification service but it's compatible with android just, if they are a way that compatible with xamarin.forms please leave a comment bellow , and if not it's ok to customizing the service by using for example web services and online database ? because this is the last solution on my opinion , thanks