We included Booked premium plugin (For Grand Tour v2.5 or higher) to let you easily manage your appointments. You can also find detailed instructions and tips from official plugin documentation here.
When you installed the plugin. You can find its setting page in WordPress Dashboard > Appointments.
To add booking calendar form to tour item. You can simply copy this shortcode below.
Then when you edit tour options. Select “Booking Method” to “HTML & Shortcode”. Then add its shortcode to “Booking HTML & Shortcode” field.
Then you will see calendar selector on tour page like below screenshot.
So when you want to make an appointment, click on available date and it will open each available time of selected date.
Click “Book Appointment” will open popup and then complete the booking form. The appointment will be sent to your WordPress Dashboard > Appointments > Pending