How to use the rot-js.VK_M function in rot-js

handleSpellbookEvent(evt) {
		let { keyCode } = evt
		let shiftPressed = evt.getModifierState('Shift')
		// evt.preventDefault()
		const exit = [ROT.VK_ESCAPE, ROT.VK_Z, ROT.VK_S, ROT.VK_M]
		const confirm = [ROT.VK_RETURN, ROT.VK_E]
		const up = [ROT.VK_UP, ROT.VK_NUMPAD8, ROT.VK_W, ROT.VK_K]
		const down = [ROT.VK_DOWN, ROT.VK_NUMPAD2, ROT.VK_S, ROT.VK_J]
		const left = [ROT.VK_LEFT, ROT.VK_NUMPAD4, ROT.VK_H]
		const right = [ROT.VK_RIGHT, ROT.VK_NUMPAD6, ROT.VK_L]
		const ul = [ROT.VK_NUMPAD7, ROT.VK_Y]
		const lr = [ROT.VK_NUMPAD3, ROT.VK_N]
		const ur = [ROT.VK_NUMPAD9, ROT.VK_U]
		const ll = [ROT.VK_NUMPAD1, ROT.VK_B]
		/* If the key event isn't repeated within the last 160 milliseconds (too soon), then we proceed but we keep track of this
	  key movement time */
		if (evt.type === 'keydown' && up.concat(down).includes(keyCode)) {
			if (this.keyTimer === null) {
				this.keyTimer = new Date()
			} else {
				let start = this.keyTimer.getTime()

document.body.addEventListener('keydown', (e) => {
    if(e.keyCode !== ROT.VK_M) return;

    GameState.manualMove = !GameState.manualMove;
    if(!GameState.manualMove) {
      GameState.game.engine.unlock();
    }
  });