Adding a BigFix ActionScript to a task via API

I am using PowerShell to schedule tasks via the API. One of the tasks I need to schedule is simply a server reboot at a specified time. Manually, I do this by creating a custom action, filling out the appropriate options for start time, end time, reapply, and retry. The I go to the ActionScript tab and put in “restart 5” in the window and select “BigFix ActionScript”

I don’t see how to do this via API. Can anyone point me in the right direction, or - is there a better way to skin this cat?

First example under POST /api/actions does exactly that - ad-hoc action on the go:

https://developer.bigfix.com/rest-api/api/action.html