qmk_firmware/keyboards/handwired/pytest/macro/keymaps/default/keymap.json

{
    "keyboard": "handwired/pytest/basic",
    "keymap": "default_json",
    "layout": "LAYOUT_ortho_1x1",
    "layers": [["MACRO_0"]],
    "macros": [
        [
            "Hello, World!",
            {"action":"tap", "keycodes":["ENTER"]}
	]
    ],
    "author": "qmk",
    "notes": "This file is a keymap.json file for handwired/pytest/basic",
    "version": 1
}