Those are the variables you use in an Alarm (which are different than other classes of codes that are used for the API). The easiest way to find the relevant Alarm variable is to go to Alarms, go to Execute Command and select them from the drop down menu to populate the box. There is a limit of 50. I made a list of some of the most critical ones at the bottom of this page: GitHub - andywalden/mfe2snow: Open ServiceNow tickets from McAfee ESM for what I suspect is a similar purpose.
Very similar effort, using evanios in place of home-brew server, as its a supported infrastructure piece.