Bookly Waiting List Addon GPL Overview:

Add your clients to a waiting list when you’re fully booked. That way, when an appointment becomes available, you can fill it immediately. This way you avoid losing time and money. When a time slot opens, a notification is sent to the service provider with the list of customers in line. When the service provider clicks the relevant link next to the client’s name to approve an appointment, the customer’s status will be changed from ‘on the waiting list’ to ‘approved’. Maximize the time in your day with the Bookly Waiting List add-on. Important: This plugin is an add-on that requires the Bookly PRO installed and activated.