<h1>Need a zero-width space on your clipboard?</h1>

<p>1. Select All in this textarea</p>

<textarea>&#8203;</textarea>

<p>2. Copy</p>

<br><br>
<hr>

<p>Alternate version...</p>

<label>
  Click once to copy
  <textarea onclick="this.select(); document.execCommand('copy');">&#8203;</textarea>
</label>

body {
  width: 320px;
  margin: 20px auto;
  font: 100% system-ui;
}

label {
  background: darkorchid;
  color: white;
  display: block;
  width: 100%;
  padding: 1rem;
  text-align: center;
  border-radius: 4px;
  cursor: pointer;
}
label textarea {
  position: absolute;
  top: -9999px;
  left: -9999px;
}