An additional security alarm - which wire should I disconnect to unable start the engine?

It is not that simple; the security system is integrated into the CAN of the car. I can give you the security wiring diagrams so you can see how the system works and what I am talking about. You can try disconnecting wires to see what happens, but this can disrupt the operation program and cause the car to need to be reprogrammed. Check out the diagrams (below). Please let us know what happens.

Thank you, Ken, for your reply. But I mean other think, I do not want to modify factory security system, do not connect to CAN system. I would like to disconnect one wire by my magic box (like hidden switch function) and for example fuel pump is disconnected from power supply and the engine do not start (it was used in older cars).
I hope I well described it now.

So, you want to interrupt a wire to a switch for added security. I got you, there is a dark blue with orange wire coming from the power distribution center under the hood. to the fuel pump I would cut and install a switch. Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Thank you, Ken for your reply.
But I can see that it is not so easy to get this wire pin no 17.
1. The 20A fuse no 70 is the supply only for fuel pump or for else too?
2. Do you know any other circuit which could I use for safe the engine to start?

It is hard to say if what you are trying to do will work, the car runs on a specific program, but you never know. Be careful not to short anything out. here are the complete wiring diagrams so you can see how the system works. Check out the diagrams (below). Please let us know what you find.

Thank you for your reply. Could you please tell me where these two junctions are located, marked red circle? It is marked as XY43 and XY51. I would like to find the route of the wire harness to the fuel tank.

They will be inside the wiring harness connecting to the fuel pump module.

Could you please add a diagram for where it is located? Is it inside the car or under body?

It doesn't say, if you think this is the problem run a new wire from both points, this is a common wiring repair, let me know what happens.

Could you please tell me the name of these points because it is not so clear? Is it XY4300A and XY510A? I would like to find these points.

Yep, those junctions are somewhere in the harness they don't say where, you must remove the covering to find them.