MSStream video does not play automatically with autoplay=true

I embeded the MSStream video into the web page using the following tab;

<iframe src="https://web.microsoftstream.com/embed/video/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx?autoplay=false&showinfo=true" allowfullscreen="" style="border:none;" width="320" height="180"></iframe>

but autoplay didn't work and I couldn't find the reason.

Does anyone know in what case or condition autoplay doesn't work?

Any information will be appreciated.

Thank you.