No sound on selected videos or other multimedia from the web

Thanks for the help.
But, autoplay on or off has no effect. I have tried Brave on 2 different Win 10 computers and neither will allow audio/flash to run on HDTracks. Conversely this site works just fine in the chrome browser - so I know flash is installed and running correctly. I’ve tried every combination of permissions and nothing makes a difference.
I can’t understand how you got it working?