html iframe how to not autoplay code example

Example 1: disable autoplay in html iframe

<iframe width="{$width}" height="{$height}" src="http://blank.com/embed/{$id}" allowfullscreen="" controls="" autoplay="" frameborder="0" scrolling="no"></iframe>
<iframe width="{$width}" height="{$height}" src="http://blank.com/embed/{$id}" allowfullscreen="" controls="controls" autoplay="false" frameborder="0" scrolling="no"></iframe>
<iframe width="{$width}" height="{$height}" src="http://blank.com/embed/{$id}" allowfullscreen="" controls="0" autoplay="0" frameborder="0" scrolling="no"></iframe>

Example 2: youtube iframe autoplay not working

<iframe id="existing-iframe-example"
          width="640" height="360"
          src="https://www.youtube.com/embed/-SFcIUEvNOQ?autoplay=1&mute=1&enablejsapi=1"
          frameborder="0"
          style="border: solid 4px #37474F"
          ></iframe>