Custom Code to make video play in full screen automatically

Hello! Is there a way to have a video embedded into the squarespace website (stored on Squarespace, not linked to another website) and when you click on it to play it automatically goes into fullscreen mode? My client is requesting this and I'm not sure if its possible to have css code that could do this.

His website is https://davidjean.squarespace.com/cine for reference! Thank you so much in advance 🙂