How do I add video to portfolio pieces using Oshine theme?

I want to add a portfolio page that uses video. I’ve tried upload MP4s and gifs but none work. I know it’s better to not self-host, but with YouTube or Vimeo links you have to click the privacy boxes and press play - I just want them to play automatically. A gif would be fine for most but it just shows a static image.

Can anyone help?