qmk_firmware/keyboards/handwired/itstleo9/rp2040/keyboard.json

{
    "bootloader": "rp2040",
    "processor": "RP2040",
    
    "matrix_pins": {
        "cols": ["GP10", "GP11", "GP12"],
        "rows": ["GP21", "GP20", "GP19"]
    }
}