Here’s a script that will toggle a button.

Create a button and a variable called vT. On the button add this script.

vT= !vT

if(vT == true){
window.frames[0].frameElement.contentWindow.player.setVolume(1).then(function(volume) {
}).catch(function(error) {
switch (error.name) {
case ‘RangeError’:
break;
default:
break;
}
});
}
else
{
window.frames[0].frameElement.contentWindow.player.setVolume(0).then(function(volume) {
}).catch(function(error) {
switch (error.name) {
case ‘RangeError’:
break;
default:
break;
}
});
}

Is there a way to get the controls to work for HTML5 output?

This should work with HTML5 output.