Multiple/single bookings in one session

Hi, I just installed and tried Webba Booking.

I really needed a simple, clear way for visitors to my gallery to book a time slot. The plugin I currently have in use doesn’t work fine on mobile and looks quite cluttered.

Webba Booking is very clear. But it is not as simple as it looks.

I want people to be able to choose between booking for 1, 2 or more people (= a family) per time slot. They don’t pay for this, it is free entrance.

I’ve tried several possibilities, but for some reason the numbers appear randomly at the bottom of the time slots, and therefore people can’t make a choice for the desired number of visitors per time slot.
I was expecting a list of choices. But there isn’t.

By the way, this booking page is still set to private. I don’t want people to book accidently on that page while it does not work properly. I can send screenshots.

Could someone please help with setup multiple/single bookings in one session?

The page I need help with: [log in to see the link]