Proceed to the next video of the custom post type but remain on the same post

This seems to work for now..

Added onended="onEndVideo()" to the video element like so.

<?php $mrssfeed_url = get_post_meta(get_the_id(), 'nowthisearth_media_url', true);?>
<video onended="onEndVideo()" id="nowthis-video" class="nowthis-video" style="" width="1280" height="720" autoplay="true" controls>
   <source src="<?php echo $mrssfeed_url ?>" type="video/mp4">
   Your browser does not support the video tag.
</video>

Then did this for the javascript..

function onEndVideo() {
   document.querySelector("a.next-post").click();
}