Pymavlink cannot control the vehicle through the RC channel

I made an unmanned ship and brushed the rover firmware, but I couldn’t control the unmanned ship through the demo provided on the official website. What’s going on?
The core code is as follows:
if channel_id < 1 or channel_id > 18:
print(“Channel does not exist.”)
# Mavlink 2 supports up to 18 channels:
# Messages (common) · MAVLink Developer Guide
rc_channel_values = [65535 for _ in range(18)]
rc_channel_values[channel_id - 1] = pwm
master.target_system, # target_system
master.target_component, # target_component
*rc_channel_values) # RC channel list, in microseconds.

Hi @Tiger_0702,

Have you got the vehicle moving using a regular RC? I know it’s tempting to try and skip buying an RC if the eventual aim is to operate it completely remotely with a joystick but it is still working getting an RC for the initial vehicle setup and tuning.