How to make a button fixed its position on a gameobject model ?

Hi guys,
I am creating a interactive environment for heritage buildings with buttons and a first person player.
I am wondering how to make my button fixed it’s position on a building.
Currently my buttons created are moving around following the camera view of the player but I wanted to make it stay on that particular building only.
In order to make the buttons attach to the buildings is there any scripts that I have to attach to the buttons?..

You need to create a new canvas and set its space to world space, if you search in google for health bar systems thats basically the same idea behind