Not sure which is the “CDU” button but you need to hit the POS INIT button on the FMS, then the button next to your position. There’s a guide here: [HOW-TO] Citation CJ4 - FMS Programming Guide | MSFS 2020
Not sure which is the “CDU” button but you need to hit the POS INIT button on the FMS, then the button next to your position. There’s a guide here: [HOW-TO] Citation CJ4 - FMS Programming Guide | MSFS 2020