From here, you can try to use Vuforia's Mid Air option, which, instead of placing the objects attached to the ground, places them at a distance from it. This can be useful for placing objects on walls, such as frames, pictures, and so on, or when working with flying objects such as drones. Their use is very similar; instead of creating a Plane Finder and Ground Plane Stage, you create a Mid Air Positioner and Mid Air Stage.
You can also download the Vuforia core samples from the Unity Asset Store (https://assetstore.unity.com/packages/templates/packs/vuforia-core-samples-99026), which includes a full example of the Ground Plane and its features.
