I am trying to do verticle plane detection

Im using 2019.4.38f1 version of unity 3D editor
I am facing this type error once I import the arcore-unity-sdk-v1.2.0 version

Error: Assets\GoogleARCore\SDK\InstantPreview\Scripts\InstantPreviewManager.cs(33,23): error CS0234: The type or namespace name ‘SpatialTracking’ does not exist in the namespace ‘UnityEngine’ (are you missing an assembly reference?)

Please help me out to solve it.

If you started a new project, use the latest LTS and use XR Management to load ARCore properly.
Otherwise I am not too sure how to fix this issue. Where did you get the sdk?

Thank you, I will try that. And i got that sdk from this git repo