QR Codes not displaying in emails, Rails

I'm dealing with a legacy Rails website. I am trying to put QR codes in an email (which otherwise works normally on the website), uses QRCode.js.

<% @tires.each do |tire| %><h3>TIRE <%= tire.id %> QR CODE</h3><div class="barcode-main" id="barcode_<%=tire.id%>"></div><script>     var qrcode = new QRCode("barcode_<%=tire.id%>", {    text: "http://jindo.dev.naver.com/collie",    width: 128,    height: 128,    colorDark : "#000000",    colorLight : "#ffffff",    correctLevel : QRCode.CorrectLevel.H    });</script><% end %> etc

In Gmail inspection the element is:

<div id="m_142369116572343918barcode_49"></div>

In Outlook inspection the element is:

<div id="x_barcode_49"></div>

No class, and the id is altered with gibberish in front of it. Works normally as an attachment and everywhere else.

... I have also now tried the same with RQRCode and Google Chart QR - can get them to show on the website, but not in an email. With RQRCode the elements show up as <u></u> and with Google Chart QR it is a broken image.