After installing the package, you can already start using FlexMotion by adding a FlexMotionAnimator component to the GameObject you want to animate.

The component can be added by pressing the Add Component button, selecting FlexMotion and then FlexMotionAnimator.

The FlexMotionAnimator relies on the built-in Mecanim animator component so make sure that the GameObject has one.

Note that the Mecanim Animator component doesn't have any controller set. That's normal and if it does it will be overridden by the FlexMotionAnimator logic.

The Avatar setting must be set if the model is using a humanoid rig. If you need help regarding avatars, check the Unity manual dedicated to this topic. Mecanim Animator's Update mode setting will be ignored and the two last settings (Apply Root Motion and Culling Mode) work as expected.

When added, the FlexMotionAnimator component should look like that:

When it comes to the FlexMotionAnimator's settings you can keep their default values and move to the next section: Play animation clips. But if you want to know more about them, feel free to visit the change Animator settings section.