Should a vehicle immobilized by a breakdown on the hard shoulder signal his situation?

Yes, with the emergency signal of the vehicle, the hazard warning triangle and, if necessary, with position lights: Correct
When a vehicle is immobilized due to a breakdown, it is crucial to signal the situation clearly to other road users. This can be done using the vehicle’s emergency signals, a hazard warning triangle, and position lights (if necessary). These signals alert others to the breakdown and help prevent accidents.
No, because the place used to immobilize it is the proper one for this kind of situation: It is incorrect, while the hard shoulder is a safe place, signaling the situation is still necessary for safety.
No, because the vehicle is not in the roadway: It is incorrect because the vehicle may not be on the roadway, but signaling is still required for safety.