title: How Disabled Feature Policy in iframe?
body: <p>I have a listener on the page that copies the text.</p>
  
  <pre><code>obj['this'].shadowRoot.querySelector(`div.${item}`).addEventListener('click',async (event)=&gt;{
   event.currentTarget.style.background = '#faf671'
   let object = event.currentTarget
   let value = object.querySelector('p.value').innerHTML
   await navigator.clipboard.writeText(value)
   let timer = setTimeout((event)=&gt;{
       object.style.background = '#4c6499de'
       clearTimeout(timer);
     }, 250);
  })
  </code></pre>
  
  <p>Then I open the page in iframe and got this error:</p>
  
  <pre><code>waves-provider.mjs:831 Uncaught (in promise) DOMException: Disabled in this document by Feature Policy.
  </code></pre>
  
  <p>I added allow</p>
  
  <p>But in internet i see example </p>
  
  <pre><code>allow="document-write https://www.google.com"
  allow="fullscreen 'none'; geolocation 'none'"
  </code></pre>
  
  <p>but it's not work.</p>