qmk-dactyl-manuform-a/keyboards/rotr/keymaps/default/keymap.c

#include QMK_KEYBOARD_H

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    [0] = LAYOUT(
        KC_MPRV, KC_MPLY, KC_MNXT
    )
};