For example, I put the billboard  inside a moving car.

Hi,

To assist you better, we need to know if you are using a tracked camera and if you intend to move the camera along with the car's movement.
For example, If you're looking to move the camera along the car's path with a tracked camera, you can find detailed instructions here: https://my.aximmetry.com/post/4353-how-to-tilt-and-pan-the-camera-freely-wh

Note, that we strongly recommend animating the car's movement within Aximmetry. Doing so ensures that all features of the camera compound and Aximmetry operate correctly. Additionally, if you proceed this way, the solution will be simpler.

Warmest regards,

Thanks for the reply.

What I need to do is either put the billboard inside the car In Unreal, so if the car moves, the billboard  moves with it .

or it stays in its normal place in the Aximmetry and I connect the transformation to a pre-determined place inside the car.

.