JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" value="Save" onclick="var self=this; ShowConfirmation('Confirm', 'Some message...', function () { SaveReleaseStage(self, 'Reassigned', 'ReleaseStage/ReassignProcess'); });" />

JavaScript

function ShowConfirmation(title, msg, callback) {
    callback();
}

function SaveReleaseStage(self, title, msg) {
   console.log(self); 
}