newtonian mechanics - Is the force which throws a body on a rotating disk outwards centrifugal force?

If some object is kept in a radial groove made on a disk and the disk is rotated with say constant angular velocity.

Now as we know that the object moves outwards ie away from the centre of the disk. I want to know which force is it which throws the object outwards.

As centrifugal force is a pseudo force and hence when the observer is in ground frame it shouldn't be present so which force exactly pulls it out.