FluentBooking Multiple Sessions

I just found out that there is an option for the user to book multiple bookings at once. However, I the UX/UI for the user is not that good regarding that. Once you choose a date and then a time then immediately pops a button to continue next to the time. But you have no idea that you have an option to select multiple times.

I think there should be some rethinking about this and to see how to make it more convenient.