For Airbnb reservations, you can select "Alter Reservation" on the conversation page with that guest to make alterations. However, if your Airbnb account has a limited connection to Hospitable, you will have to manage any alteration requests on Airbnb.
For reservations booked through Vrbo, Booking.com, you can change the check-in/check-out time through Hospitable. Any other alterations, such as property, dates, guest count, fees, etc., must be completed directly on the booking platform.