You can add a post in the slider on the homepage by enabling the Featured in Homepage Slider option in the editor.
If you don’t see the option to add a post in the slider in right sidebar, look at the bottom, below the editor, maybe it’s there.
Make sure to add a Featured Image to your posts, as this will be shown in the slider.
If a post has a video added in the Video at the Top section in editor, then you can display it in a pop-up in the slider.
This option can be disabled in the Theme Options > Homepage Slideshow:
Change the Order of Posts in the Slider
By default, posts are ordered by date, but you can change it from the Posts > Featured Posts page:
In the WPZOOM > Theme Options > Homepage Slideshow page you can change additional options for the slider
Notes about Automatic Video Thumbnails
Automatic Video Thumbnails are generated only for popular video websites, like YouTube, Vimeo, DailyMotion.
The video must not be set to “private” or otherwise hidden from public access.
The video must have a thumbnail image available via oEmbed.
Your server must allow remote file requests and downloading of remote files.
Your server must not block the use of oEmbed.
Some video services will limit the amount of requests allowed from certain sites. If you have MANY videos on your site that are all using the auto thumbnail functionality, some of the thumbnails might not work due to the video service limiting your requests to their API
