for streamable link

<div class='embed-wrapper'><div class='embed-container'><iframe src="https://streamable.com/e/$1" frameborder="0" allowfullscreen></iframe></div></div>

(?:<a.?)?(?:https?://)?(?:www.)?(?:streamable.com/(?:(?:/e)?/))([a-zA-Z0-9_-]{2,12})(?:.*?/a>)?