qmk-keychron-q3-colemak-dh/keyboards/helix/rev2/keymaps/led_test/led_test_init.c

#include QMK_KEYBOARD_H

void keyboard_post_init_user(void) {
    rgblight_enable_noeeprom();
    rgblight_mode_noeeprom(RGBLIGHT_MODE_RGB_TEST);
}