UIWebView in Xamarin From not display Video

hi,
I implement UIWebView in Xamarin.Froms for Android and IOS. Customer provide video on HTML5 files and I 'll display this HTML5. But video in UIWebView is not display.
Could you tell me how to display video on Xamarin.From using UIWebView.

File HTML like this:

!DOCTYPE html>
html>
head>
meta charset="utf-8">
title>
meta name="description" content="">

/head>
body>
div id="engagement-patient_use-main" class="hidePrevBttn hideNextBttn hideRatings">
video id="pre-video" class="video-js vjs-default-skin" preload="none" width="1080" height="1920" data-setup="{}" >
source src="Folder1/Folder2/assets/flight.mp4" type='video/mp4' />
/video>
/div>
/body>
/html>

Thanks so much.