Starting SITL instances with PX4 console

1 - First question: When I run more than one px4 instance, I want to use the “commander takeoff” at PX4 shell. There is no console with “pxh>” when I start writing on the prompt. So I opened another terminal trying to send the command like it is explained at the picture taken from System Startup | PX4 User Guide.

Regardless the number of the instance chosen, just the first instance accepts the commander takeoff as it is described at this screenshot.

I want to know if and how I can call the right instance from the terminal.

2- Second question: I’ve tried to run multiple instances via: “Tools/” and separately from simulator with “bin/px4 -0 $N -d “$build_path/etc” -w sitl_${MODEL}_${N} -s etc/init.d-posix/rcS” and there is no “pxh>” shell. How can I make it to appear on the other instances like when I run “make px4_sitl gazebo” ?