How to takeoff multi UAVs at the same time?

I am studying about multi UAVs formation flight via one GCS.
I have already tried to connect several drones to a GCS with ‘swarm function’ of ‘missionplanner’ or ‘qgroundcontrol’. But wherever no function to multi UAVs take off at the same time. How can I take off at the same time as a drone like an ‘intel’ swarming video?
Thank you for reading.

I am working on a simulation formation of multi UAVs . I Can use QGroundControl the takeoff of five drones one by one. But I can’t control multi UAVs takeoff at the same time. I would like to know if you have solved the problem of taking off multi drones at the same time, and how?
Thank you for reading