GUTS works slightly differently than others. When buying tickets for a seated event, you choose a section. At least 24 hours before the start of the event, the seats will be assigned automatically within the section you have chosen.
Choose the tickets in the desired section. In the map you can see what seats belong in the section. You do so by using the '+' button.
In the lower left corner is displayed how many tickets you can purchase per phone number.
After selecting your tickets, choose 'Confirm'. From this moment, you have 15 minutes to complete your order.