qmk_firmware/keyboards/handwired/onekey/keymaps/default/keymap.c

// Copyright 2020 QMK
// SPDX-License-Identifier: GPL-2.0-or-later
#include QMK_KEYBOARD_H

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    LAYOUT_ortho_1x1(KC_A)
};