Unable to arm drone using pymavlink

[colabthirteen]

I was trying to arm and control the drone via 3DR radio telemetry with this code

from pymavlink import mavutil
import time

def connect_drone(connection_string, baud_rate=57600):
    print(f"Connecting to drone on {connection_string} at {baud_rate} baud")
    drone = mavutil.mavlink_connection(connection_string, baud=baud_rate)
    drone.wait_heartbeat()
    print("Heartbeat received from system (system %u component %u)" % (drone.target_system, drone.target_component))
    return drone

def set_mode(drone, mode):
    if mode not in drone.mode_mapping():
        print(f"Mode {mode} not found in mode mapping")
        return False

    mode_id = drone.mode_mapping()[mode]
    drone.mav.set_mode_send(drone.target_system, mavutil.mavlink.MAV_MODE_FLAG_CUSTOM_MODE_ENABLED, mode_id)
    print(f"Mode set to {mode}")
    return True

def arm_drone(drone):
    print("Arming the drone...")
    drone.mav.command_long_send(
        drone.target_system,
        drone.target_component,
        mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
        0,
        1, 0, 0, 0, 0, 0, 0
    )
    drone.motors_armed_wait()
    print("Drone armed!")

def disarm_drone(drone):
    print("Disarming the drone...")
    drone.mav.command_long_send(
        drone.target_system,
        drone.target_component,
        mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
        0,
        0, 0, 0, 0, 0, 0, 0
    )
    drone.motors_disarmed_wait()
    print("Drone disarmed!")


def set_throttle(drone, pwm_value):
    print(f"Setting throttle to PWM value: {pwm_value}")
    drone.mav.rc_channels_override_send(
        drone.target_system,
        drone.target_component,
        65535, 65535, pwm_value, 65535,
        65535, 65535, 65535, 65535
    )

if __name__ == "__main__":
    connection_string = '/dev/ttyUSB0'  # Replace with your connection string
    baud_rate = 57600  # Replace with your baud rate if different

    drone = connect_drone(connection_string, baud_rate)

    # Set the desired mode (e.g., 'GUIDED', 'STABILIZE')
    desired_mode = 'GUIDED'
    if set_mode(drone, desired_mode):
        arm_drone(drone)
        
        set_throttle(drone, 2000)


        time.sleep(5)  # Keep the drone armed for 5 seconds
        disarm_drone(drone)

When the script was in arming mode it sends the AT command but it doesn't arm until I arm the drone with the RC.