fix notification

pomodoro_bot/bot.py

@@ -10,7 +10,7 @@ API_TOKEN = os.getenv("BOT_TOKEN")
 
 bot = Bot(token=API_TOKEN)
 dp = Dispatcher(bot)
-timer_manager = TimerManager(bot)
+timer_manager = None
 
 menu_kb = InlineKeyboardMarkup(row_width=2)
 menu_kb.add(
@@ -43,7 +43,9 @@ async def handle_callback(call: types.CallbackQuery):
 from pomodoro_bot.redis_client import init_redis
 
 async def on_startup(dispatcher):
+    global timer_manager
     await init_redis()
+    timer_manager = TimerManager(bot, dispatcher.loop)
 
 def run_bot():
     executor.start_polling(dp, skip_updates=True, on_startup=on_startup)