Sinch API in an Angular 2 project times out on onCallProgressing

It worked for me by using the sinch-rtc as Savaj Patel mentioned.

Example:

sinchClient = new SinchClient({
    applicationKey: 'YOUR KEY',
    capabilities: {messaging: true},
    onLogMessage: function(message) {
        console.log(message);
    }
    });

sinchClient.start(CREDENTIALS).then(function() {
        console.log('Success!');
    })