qmk_firmware/keyboards/handwired/onekey/teensy_35/keyboard.json

{
    "keyboard_name": "Onekey Teensy 3.5",
    "processor": "MK64FX512",
    "bootloader": "halfkay",
    "matrix_pins": {
        "cols": ["D5"], // 20/A6
        "rows": ["B2"]  // 19/A5
    }
}