Additions.

I asked this question because I thought I had reproduced the movement of an object (not a camera) using OptiTrack's rigidbody.

Hi,

Based on your email exchange with our support, I think you solved this problem. But I will write it down here for others.

When installing plugins you should follow what is written here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/obtaining-graphics-and-virtual-assets/creating-content/creating-content-for-aximmetry-de/ue5-how-to-install-third-party-code-plugins-for-unreal-editor-for-aximmetry/#prerequisites 
Note, that in both marketplace plugins or other plugins, you need the original Unreal installed and the requirements paragraph fulfilled.

Also, Aximmetry natively supports the use of Optitrack.
If your goal is however, to use the tracking data stream provided by Optitrack to control a Metahuman for example, then you either need to run the scene in Live Sync mode, or you need to acquire or create a blueprint/plugin that would allow Optitrack to work in a cooked scene.

Warmest regards,