Confirmation field in the form settings
The new functionality we have included in the forms is the possibility to add a confirmation field in the form settings. This way your customers before booking with you will have to check the box of the confirmation field and can access the external link that you have included.
This customization of the events must be done from the flows. It is necessary to create the form flows to customize the information requested to the customers when they are going to make a booking with you.