Grab embedded MixStep URL location from playback widget; won't work with multiple iFrames

CLLV Download Finder

// ==UserScript==
// @name        CLLV Download Finder
// @include     http*://*cllv.in/music*
// @namespace   https://github.com/usrme
// @description Grab embedded MixStep URL location from playback widget; won't work with multiple iFrames
// @version     1
// @grant       none
// ==/UserScript==

var iframe_uri = document.getElementsByTagName('iframe')[0].src,
	arr = iframe_uri.split('/'),
	id = arr.slice(-1)[0],
	uri = "https://mixstep.co/" + id;

console.log(uri);