Avictim of foreign body airway obstruction become unresponsive. what is your first course of action?

Use a head tilt (tilting the head backward) and chin lift to prevent the tongue from obstructing the upper airway, and look for the foreign body that is causing the obstruction.

Explanation.
The backward head tilt and chin lift will prevent the tongue from obstructing airflow.
If the foreign object can be seen and removed, do so. Usually, it is not wise to use the fingers unless the foreign object is visible and accessible.

The next step is to perform CPR because the patient is unresponsive.