Newbie- can't flash klipper on octopus for voron 2.4

Basic Information:

Voron 2.4
rasperry pi 2 with wifi dongle (mainsail installed)
BTT Octopus with stm32f407 - trying to install Klipper

Raspberry powered with separate +5V- downloaded mainsail without a problem- yeah!
Generated “firmware.bin” and uploaded to SD card.
Could not find " /dev/serial/by-id" - to verify flash after powering with with SD card- I do have a “serial0 and serial1” file but no serial directory.

Can anyone confirm STM32F407 config? (frequency, comm interface, etc…)

I also tried flashing using boot0 jumper- but no dofu device was listed (as indicated byVoron2.4 software instruction).

IS F407 the problem? I don’t see much mention of it here.

Thanks for any help-

Check if this is applicable: Debian Bullseye Bug causing Klipper to no longer find the printer board