Xamarin forms right design pattern with api's

I want to make an app which would be cross platform, android/ios/uwp. I have it right now in mvc architecture, could change it to mvvm. I would like to implement in future azure push notificion which needs separated api project for it. So here's my question , how should I do my whole project? Should I implement all api(my project api and push notification api) as one and create another xamarin forms project in which I would just get my data using for example rest api ?

Thanks in advance for help. :)