background video one page not working

Hi!
I have some problem playing background videos in one page layout (i'm using op-plan-subscription.html as a base for developing).
In paricular i'm not able to integrate it in this page.
This is an extract of my code:

<section id="slider" class="slider-element include-header">

<div class="row align-items-stretch no-gutters min-vh-100">

	<div class="col-lg-4 col-md-7 order-md-last" style="margin-top: 10em;">
		<div class="container clearfix">
			<h2 class="mx-auto bottommargin font-body" style="max-width: 700px; font-size: 40px;">Ottieni la garanzia per i tuoi prodotti!</h2>
			<p class="lead mx-auto bottommargin" style="max-width: 800px;">
				<a href="#" data-scrollto="#section-footer" data-href="#section-footer">Registrati</a> per ottenere assistenza e garanzia sui tuoi prodotti acquistati da Db-Line.</p>
			<div class="clear"></div>
		</div>
	</div>

	<div class="col-lg-8 col-md-5">
		<div class="video-wrap dark">
			<video id="slide-video" muted autoplay loop preload='auto' playsinline>
				<source src='images/videos/intro1.webm' type='video/webm' />
			</video>
			<div class="video-overlay" ></div>
		</div>
	</div>

</div>

</section><!-- #slider end -->

I'm doing some error?

Thanks a lot for this fast reply, now it works perferctly!

Massimo