How get Latency Broadcaster Value from App

I would like to know how can I get the Latency Broad Value from my APP. I would like to check this value to restart the the client’s player by javascript.

twitch.ext.onContext(function(context) {
    
    var latency = context.hlsLatencyBroadcaster;

    if (latency > 15) {
       // restart    
    }
});