Open your seated event.
Click 'Seating chart' in the left-hand menu.
If you're using recurring events, choose the day or time you want to hold seats.
You will see your seating chart. Select the seats to put them on hold.
Choose 'apply changes'. (You can apply up to 10 changes per day).
Now, your seats are on hold!
💡 Things to note:
You can't increase the number of holds/modifications you can do per day.