Why is the video not playing?

Question

css

Hello.
Wrote a page and uploaded it to the hosting for practice wladislav.zzz.com.ua/
In theory, a video should be played against the background of the first slide.
In practice, the video does not play and writes that the path is not correct ...
I'm sure that the path for the file is correct, but the video is not played. I don't know what the problem is...
Also, why doesn't the video play automatically? I specified the autoplay attribute for the video tag .. And it happened that when checking in the main browsers, when the video was first opened, it started automatically, but when it was restarted, the video was at the very beginning ...
Thanks for the answers and your time :)

Answer 1

but there is no video - wladislav.zzz.com.ua/app/video/background.mp4
404
Added:
And here it is:
wladislav.zzz.com.ua/video/background.mp4