Radio failsafe set RTL

On my quad with pixhawk 2.4.8 clone , I have radio failsafe on QGC set to RTL , when I do a check on ground with quad armed and props spinning , when I turn off radio I get radio failsafe announcement, no RTL announcement but the quad announces disarming and disarms, how do you check that the failsafe is working properly without actually flying the quad

Good day, just look this like about what you need… hope can help

https://ardupilot.org/copter/docs/radio-failsafe.html

If it’s not actually flying it wont change into RTL mode

Ok , thanks for the help
Tony