insert video in bootstrap 4 code example
Example: video bootstrap
<div class="embed-responsive embed-responsive-21by9">
<iframe class="embed-responsive-item" src="..."></iframe>
</div>
<div class="embed-responsive embed-responsive-16by9">
<iframe class="embed-responsive-item" src="..."></iframe>
</div>
<div class="embed-responsive embed-responsive-4by3">
<iframe class="embed-responsive-item" src="..."></iframe>
</div>
<div class="embed-responsive embed-responsive-1by1">
<iframe class="embed-responsive-item" src="..."></iframe>
</div>