Message Cannot Send to Raspberry Pi 4

Hello, Im using rpi4 + flight controller board as my flight controller. and the software using BlueOS.
Recently Im trying to make my gimbal can send message and receive packet from the pc, so im make a convent board using Arduino UNO + CAN Shield to translate CAN protocool message to mavlink packet . and using uart to send to ap. and ap connet to pc using UDP. Like this diagram:

This thinking can worked by cubepilot, but using rpi4 can not receive message by UART.
Im trying to using Endpoint / Bridge, but they are not working.
Does anyone know how to receive message using BlueOS? thx.