Sure, here is a step-by-step guide on how to buy tickets for today's AS Monaco football match:

1. Choose the match date and time you want to attend.

2. Go to the official AS Monaco website or their ticketing partner's website (such as Ticketmaster or StubHub) and search for the match you want to attend.

3. Select the number of tickets you want to purchase.

4. Review your order and confirm that everything is correct before completing the transaction.

5. Make sure to pay attention to any additional fees or charges associated with purchasing tickets online.

6. Print out your tickets or receive them electronically through email or text message.

7. Arrive at the stadium early to ensure you have enough time to get through security checks and collect your tickets.

8. Enjoy the game!