How to correctly import content in Unity using the latest Babylon for Unity Export?

This is the latest Babylon export plugin. I downloaded the compressed package of the entire Git project. There are directories named unity/assets and unity/Packages in the file, and there are many PK projects under these directories. Of course, I used the Unity version (2021.3.15). When I tried to publish all these PK projects in Unity, an error message about missing references appeared. Could you provide a tutorial on how to import them correctly?

cc @MackeyK24