Which Command Staff member approves the Incident Action Plan and all requests pertaining to incident resource ordering and releasing?

The Incident Commander is the Command Staff member who approves the Incident Action Plan (IAP) and all requests pertaining to incident resource ordering and releasing.

The Incident Commander’s authority to approve the IAP and resource requests underscores the centralized command structure of the ICS. According FEMA training material, “overseeing the incident, sets incident objectives, and approves the IAP” which confirms their integral role in managing and coordinating all aspects of incident response within the ICS. This is outlined on page 333 of the document .

From the perspective of other personnel within the ICS, the Incident Commander is seen as the central figure who provides direction and leadership.

Source: https://training.fema.gov/emiweb/is/is200c/english/instructor%20guide/is0200c%20ig.pdf