Is your site/app iframeable?

index.html

<style>
  body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
  }
  iframe { flex-grow: 1 }
</style>
<script type=module>
  const iframe = document.querySelector('iframe')
  const input = document.querySelector('input')
  document.querySelector('form').addEventListener('submit', evt => {
    evt.preventDefault()
    iframe.src = input.value
  })
</script>
<h1>Is your site/app iframeable?</h1>
<form><label>iframe src=</label> <input value=https://wikipedia.com></form>
<iframe src=https://wikipedia.com></iframe>