Lets a colleague authorise one action the signed-in staff member cannot perform alone, such as a discount above the outlet cap or voiding an item already sent to the kitchen.

The approver enters their own login PIN as approval_pin. If their role holds the permission the action needs, the response carries an approval_token. Pass it on the operation that performs the action; it is single-use, expires within minutes, and only works for that action and subject_id (the order or order item). The approver is recorded on the result.

Requires the requesting staff member's own X-Staff-Token. Shares the login PIN lockout.