Using your phone you can log-in (*96) and log-out (*98) out of queues you are assigned to.
There is a difference between being Added to a queue and logging into a queue.
Being Added to a Queue VS Logging Into a Queue
First an extension should be added to a queue using the VoIP Dashboard. Once an agent has been added to a queue they will not immediately receive calls from the queue, they still need to be logged-in to the Queue.
Logging into Queue(s) - *96
Once you have been added to the queue, pressing *96, your extension will be logged in to all the extensions within that organization which you are Added to. You will start receiving calls from all those queues immediately. You can not login to specific queues only.
Logging out of a Queue(s) - *98
When you no longer wish to receive any calls from the queues, pick up your receiver and press *98, your extension will be logged off from all the extensions within that organization which you are Added to. You will stop receiving calls from all those queues immediately. You can not logoff from specific queues.