Translate this topic from Italian to English and there is the solution:

https://helpcenter.websitex5.com/ru/post/249734

the example is here:

https://www.test70.altervista.org/underwearshop05/home.html

... x  Marek T., (It > En)  ... the autoplay of videos containing the Audio track has always been inhibited in "mobile" devices, so in this case it is nothing new...
... instead recently PC browsers have also conformed, adapted, these directives ...
... the program automatically inhibits the sound to allow the autoplay of the background video and therefore without sound...
... the sound / audio is automatically re-enabled by interacting with the pages of the site; .. for example if you go from "HOME" to "contacts", and then from this you return to "HOME", ... then the Video it will start including the audio, but this, even if it works, obviously is not a good idea for those who know it, you could overlay the audio without the possibility of STOP to other sounds on the page ...
... ideal for backgrounds would be videos with no audio track, ... or the expected slideshow ...
...
...!... for Videos, the only alternative I know of is an EXTRA exclusive invention of mine...!...
.

... ello, ciao ...

.