Trigger Camera connected with SingleBoardComputer from the PixHawk connected with SBC

I am doing a little different thing, here are the details:
1- PixHawk 4
2- Raspberry Pi 4
3- 4K Camera (Make & Model Not selected)

RPi = Raspberry Pi 4 (Single Board Computer)
PH = HolyBro PixHawk 4

I connected the RPi with PH using the Telemetry Port 2 of PH & Serial Port of RPi. Both get connected and I can operate the PH from the RPi. Everything is fine till this.
But the real problem which I had is: I want to connect a camera with my RPi so it can save the images on the Memory device connected with the RPi, but my camera will capture the images on the GPS locations which I set in the WayPoints while uploading the Mission on the PH.

I know there are AUX ports (AUX4-5 or AUX5-6) in the FMU PWM OUT, but how to use those or something like this, I am confused about the flow.
Please help me with the flow and the solution as well.

The simpliest way is to connect your camera trigger to PWM out directly, imho.
But youl’ll need to solder external trigger transistor to your camera - to emulate manual trigger - if it does not have the external trigger plug.
You will not need to use RPI in this case. Setup and test external trigger for your camera, like explained here: