MAVLink connection between Arduino and Pixhawk

Hi guys, I try to establish a connection between my Pixhawk 4 and Arduino Uno. A temperature sensor DHT22 is connected to Arduino Uno to collect temperature data. The aim is to send the temperature data from Arduino Uno to Pixhawk 4 via Mavlink protocol and then the temperature reading can be display in Mission Planner. Now I’m stuck with the communication between Arduino and Pixhawk. Can anyone pls tell me how to do?

A simple search would lead you to this topic : MAVLink and Arduino: step by step

Don’t forget that you have to send heartbeat messages from your arduino to allow mavlink message routing via pixhawk to ground station.