Outgoing calls on a Snom 870 phone via asterisk


We have made a setup of asterisk, where we click on the number we want to call in our system


When we click on the number in the system, then the asterisk server rings the number, as soon as the call is answered, then the SIP phone snom 870 starts ringing and when we answer this call, then there is contact between the SIP phone and the person answering the call.

However, it is so that our secretaries already has a call when they want to make this outgoing call, therefore this solution is not working, it must ring the number directly from the phone without first answering the “call” on the SIP phone.

Anyone who has an idea of what we can do to fix this issue? Or who knows a lot about asterisk/snom which we can pay to help us?