Once imported, Compass Navigator Pro can be added to your scene from the top menu GameObject > UI > Compass Navigator Pro.
Alternatively, you can locate the CompassNavigatorPro prefab in Resources/Prefabs folder and add it to the hierarchy of your scene.
Select the new created Compass Navigator Pro game object and customize the behaviour and look & feel of the compass bar using the custom inspector.
Important! In HDRP, please expand the CompassNavigatorPro in the hierarchy until you find the TopDownCamera. Set its Volume Mask setting to Nothing.