Pass argument from button to JavaScript Snippet

I currently have a “Send Notification” button on a single record pop up. 

All I am trying to do is when someone clicks this button to pass the record ID to the javascript snippet. But I don’t seem to understand on how I can achieve this. 

The current code.

var params = arguments[0], $ = skuid.$;


//var model = skuid.model.getModel(‘RnDVac’), row = model.getFirstRow();
var model = skuid.model.getModel(‘RnDVac’), row = model.getRowById();

var requestType     = model.getFieldValue(row, ‘RequestType__c’);
var requestID       = model.getFieldValue(row, ‘Name’);
var requestIDNumber = model.getFieldValue(row, ‘DocID__c’);