3D printer board with STM32

I have a 3D printer board that I want to use for my own robotic project. I am having some trouble getting it to run my own code.

The board is a BTT SKR3

I was not able to find anything specific about using this with platformio
The chip is the STM32H723GV.

The good news is the board is designed to work with Marlin and platformio. So the official marlin repo has pin-definitions already for this board.

I am just switching over to platformio so I am a bit lost, Marlin is a little over my head with the layers of configuration files and setup systems it needs. I am just trying to pull out enough from Marlin to get a simple blink sketch on my board. Any support is appreciated.

I am trying to start a blank project and just move over the config lines from marlin that are related to my project

boards_dir   = buildroot/share/PlatformIO/boards
default_envs = STM32H723VG_btt
extra_configs =

but I am getting this error:

(project configuration file): 'No section: 'common''

Does anyone know Marlin any better and has attempted this before?
I am coming from Arduino and ramps so this is a bit of an upgrade.