Augmented Reality / Unity 3D

Hello, since apparently there is no good way to create augmented reality with xamarin forms at least running .net standard 2.0, is there a way I can create content in unity 3D and make some sort of insert in my APP?
The basic question is how can I make AR but I believe is not possible right now so which options can I have I just want to create a 3D building over a flat surface nothing too fancy, how can I make this possible?
Thanks