Adding a handtracking package in a game already in development

Within le VR learning courses in Unity (a project already started), I would like to change my XR interaction Toolkit 2.0.2 to the newer version 2.4 in order to add handtracking. I have imported the version 2.4 in Package manager, but it doesn’t change it in my project.

Is it possible to add a packages when the project has already started ? If so, how could I include 2.4 in my project ?