Credits: Mr. Husana909
The first thing you need to know is you can't make missiles in survival - get them from Creative inventory. Another important thing is that you must install them on the launch pad.
When the rocket is already placed, you must put a chip in it. This is needed to distinguish missiles one from another and perform multiple separate launches.
Choose the angle and the flight distance using special instruments on the rocket. There are up to six options for each setting and it will determine where the rocket goes.
Finally, put a corresponding card into the Detonation device using crafting to bind it with a rocket. You can use multiple devices with different cards in them to launch missiles separately.
Enable Experimental features in the world's Settings.