A box offering you the call will appear in the upper right corner. To accept it, simply click on Accept.

If you're working on something else and Dixa is open in the background, you'll receive a notification with the incoming call (but only if you have allowed notifications from Dixa).

If you're wondering why you aren't receiving calls, it's typically because your presence is set to 'away'. If that doesn't work, check with your admin whether you're assigned to the right queue.