Adding video with sound

Site URL: https://www.kganyc.com/the-glasshouse

Hello, 

I am seeking assistance with adding video to our company website. Please see the attached site URL. 

We currently have photos that you can scroll through. We would like to option of adding video on autoplay at full bleed with sound. Specifically on the projects page. 

Our web designer used CSS to customize this portion of the site. 

Thanks very much!

I've used https://www.sqspthemes.com/plugins/background-video-controls in the past with good results to play sound in background video.