A rotating rigid body have an angular momentum which is equal to the product of where is the moment of inertia and is the angular velocity.
If a rigid-body spins along its main Axes it will continue spinning unless there is a torque acts on it.
A torque equals to the vector product of x where is the force and is the distance from the rotation axis and its direction is acording to Right - hand grip rule.
When a torque acts on a rotating rigid body it will change the value and the direction of the angular momentum, /= (see animation 1)
The scientific explanation which is present before the video is of high quality since it explains a very complex subject in a good and invested way, unfortunately, because I don't come from physics field, I couldn't understand the theoretical material and the question clearly, perhaps you should explain it in a more simplified way to fit everyone, but certainly the question and the video on the high end, but there is still place for improvement.