Java script: how to get Workflow Id from Workflow Task Form

I need to get the Workflow Id with java script after editing a Workflow Task. What I have this far is only a script that gets the Task Id when the EditForm is opened:

$(document).ready(function () {

JSRequest.EnsureSetup();
var xId = JSRequest.QueryString["ID"];
//need to get the Workflow Id here

Any suggestions? All help would be appreciated!

Edit: tried to look for the Workflow Id with REST and Postman on the Workflow Task List but also there I can't find the Workflow Id Does this mean it's impossible?