Problems with Arming, using a Mamba F405 Mk2 with Ardupilot

Hi,i have a problem with arming the drone in the Mission Planer, i am using as a flight controller a Mamba F405 Mk2, i am not using GPS and ESC, i am using the flight modes Acro and Stabilize, but when i want to arm the drone with the RC it does not work.
The goal of this drone is linking the Mamba F405 Mk2 with Raspberry Pi,but we just flashed the Betaflight firmware and i installed the firmware Ardupilot.
Someone help me!