The Expert edition doesn't include Wikitude's Instant Tracking (a.k.a positional tracking). However, it integrates a direct communication between Wikitude and ARKit's/ARCore's Positional Tracking.
Moreover, in the Expert Edition Wikitude provides a plugin that enables you to combine our engine with AR Foundation (ARCore & ARKit) features, such as Positional Tracking, Plane, Face, Body, Extended tracking, Occlusion, etc.
If you want to use Wikitude's Instant Tracking, you can work with the Professional Edition. Please visit the table here for a detailed comparison between the Expert Edition and the Profession Edition, download all APIs from here and check the documentation here.