Material icons inside the chart view

[FMorschel]

Question:
I've not worked a lot with HTML/CSS/JS and I was trying to add an icon (specifically in this case a material one, but any other would be just fine as well).
I'd like to know if this should be possible and if so, what am I doing wrong?

Here is how I'm currently attempting this:

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
<div id="container">
  <button class="copyValue" onclick="copyToClipboard(JSON.stringify(response))">
    <i class="material-icons">content_copy</i>
  </button>
</div>
<style>
  body {
    font-size: 13px;
    font-family: "HelveticaNeue", "Helvetica Neue", Helvetica, Arial, sans-serif;
  }

  .copyValue {
    background: none;
    border: none;
    color: #ffffff; /* Change the color to white */
    font-size: 24px;
    padding: 12px;
    vertical-align: middle;
    cursor: pointer;
    outline: none;
  }

  .copyValue:hover {
    color: #dddddd; /* Change the hover color to a lighter shade of white */
  }

  .copyValue:active {
    color: #bbbbbb; /* Change the active color to a lighter shade of white */
  }

  .copyValue i.material-icons {
    vertical-align: middle;
  }
</style>

var html = `
#above content here (separated simply to help visualization)
`

tc.chartHTML(html);

Output:

Are you using the free version/paid version/trial:
I'm using the free version.