We have just set up ZOOM phones in our office of 5 staff, and its fair to say I'm having a difficult time trying to get everything working perfectly!
At present, if someone calls our main number, the call goes to voicemail if not answered within 30 seconds, or if our main number is busy.
I would like to set up a call queue so that an inbound call to our main number (if busy or doesn't answer) will automatically go to another internal extension, before going to voicemail if not answered.
I don't know if you had your question answered already, but the following is what would recommend doing to arrive at what you want.
Set your Auto Receptionist to route call the Call Queue that you establish.
In the Call Queue settings, set the Call Distribution to "Sequential", and then specify the order in which you would like Users' phones/apps to ring. (see attachment and link below to full help for Call Queues).