Doing a bit of research I now know I have to write the cookie of the selected option. then read the cookie to retrieve the value.
I found a similar question but couldn't figure out how to implement the code from the answer
<html>
<head>
<title>dropdown remember selection test</title>
</head>
<body>
<iframe id="stream_iframe" marginwidth="0" marginheight="0" width="854" height="480" scrolling="no" allowtransparency="true" frameborder="0" framespacing="0" name="stream_iframe" src="http://vaughnlive.tv/embed/video/moviebay"></iframe>
<form>
<select name="options" onchange="document.getElementById('stream_iframe').src = this.options[this.selectedIndex].value">
<option>SELECT STREAM
<option value="https://streamup.com/rooms/jumanjijoes-Channel/plugins/video/show?startMuted=false">Jumanjijoe</option>
<option value="http://vaughnlive.tv/embed/video/whenlinkattacks">Whenlinkattacks</option>
<option value="https://streamup.com/rooms/docblus-Channel/plugins/video/show?startMuted=false">Docblu</option>
<option value="http://vaughnlive.tv/embed/video/karenwaifu">Karenmaiwaifu</option>
<option value="http://vaughnlive.tv/embed/video/ninjatart">Nightsanity</option>
<option value="http://vaughnlive.tv/embed/video/frightfest0001">Frightfest0001</option>
<option value="http://vaughnlive.tv/embed/video/anime_hq">Anime HQ</option>
<option value="http://vaughnlive.tv/embed/video/moviebay">MovieBay</option>
<option value="http://vaughnlive.tv/embed/video/freakyfetish101">Horror Movie</option>
<option value="http://vaughnlive.tv//embed/video/111aaacharkmovies">111aaacharkmovies </option>
</select>
</form>
</body>
</html>
I managed to create a dropdown menu that will change the iframe SRC. I just need it to remember what they select on refresh or browser exit.