It is possible to set a waiting list and limit the number of spots available for services. This can be done during the service setup process.
Setting Up a Waiting List and Limited Spots
To begin, click on “Add Service” to create a new service.
During the setup, you can choose to enable a waiting list and set a maximum number of spots for the service under service options.You can also define a maximum number of participants for each service.
For example, if you have two different service options under the same service (like training on Saturdays and Sundays), you can specify a total maximum number of spots that apply to both combined.Example: You set the maximum to 30 players. That could mean 10 players on Saturdays and 20 on Sundays – or any other combination totaling up to 30.

or

Moving a Player from the Waiting List
When a spot becomes available, you can move a player from the waiting list into the active participant list by simply dragging their name over to the right side.

As soon as this is done:
The registered person receives a notification.
An email is also sent where they can complete the payment and secure the spot.