Do I need to pay the difference for an early bird ticket if it's sold out?

Early bird tickets must be booked in advance and there is no need to pay the price difference.
Early bird tickets must be booked more than 10 days in advance. There are restrictions. There is no need to pay the difference. The specific requirements should be marked above.
Anyway, I didn’t make up for it. You can give it a try depending on the situation.

Early bird tickets must be booked in advance, and there is no need to pay the price difference.
Early bird tickets must be booked more than 10 days in advance. There are restrictions. There is no need to pay the difference. The specific requirements should be marked above.
Anyway, I didn’t make up for it. You can try it depending on the situation.