Hello Kean,
The ability to edit existing bookings was added in the 3.8.0 version of Hotel Booking.
In the Booklium theme, Hotel Booking plugin is inbuilt and get updates with the template update. For now, the latest version of the inbuilt Hotel Booking in Booklium is 3.7.1.
Please, have a look at this article for more details.
So, for now we can offer delete bookings with wrong data and create new ones with new proper information.
Otherwise, in order to get plugin updates separately from the theme, you can purchase Hotel Booking plugin with license separately > deactivate&delete the inbuilt booking plugin > upload & activate the plugin version purchased separately.
Best Regards,
M. Evans