Basically, these are video backgrounds. These can be integrated in many different ways. Here is a list of plug-ins that make this possible: https://wordpress.org/plugins/tags/video-background/
Of course, there can also be themes that make this possible. You should be able to find them quickly using the keyword video background.
The special type of playback in your example page is an individual development, not something that can be downloaded from somewhere.
Thank you! That was what I needed. My brain block didn’t let me consider the video background as an option so I made it more complicated than I needed to.