How to connect Mission planner to custom Raspberry Pi flight controller using MAVLink

I’ve successfully established MAVLink communication between Mission Planner and my custom Raspberry Pi flight controller, receiving messages in the RPi terminal. Now, I aim to enable mission planning directly on my custom controller just like ArduPilot do. Seeking guidance on configuring Mission Planner to interact with my Raspberry Pi flight controller for mission planning. Any insights or resources appreciated. Thanks!

I have used this forum for communicating RPi to Mission Planner