If colleague notifications are configured on your company's account, you'll receive a reminder email before the deadline if you haven't yet chosen. Once the choice deadline has passed, you won't be able to choose a meal. This is because the order has now finalised and the restaurant needs adequate time to prepare the order.
If you've missed the choice deadline, it's worth checking with your Office Manager in case they have ordered 'extra portions' through the product that might be available for you.
We don't want you to miss out, so going forwards, we recommend setting yourself a personal reminder to avoid being left hungry!