From the website...seems to imply online booking!
Eligible Guests with Dining and Experience Reservations Cancelled During Closure
Guests who had an active dining or experience reservation on or before September 2, 2020 that was cancelled as of May 28 due to the temporary closure of Walt Disney World Resort may—beginning on June 30—make a new reservation online up to 60 days in advance. Eligible Guests who are unable to make a reservation
online may call (407) 939-6690 or (800) 800-9800 for Disney Vacation Club Members.
Eligible Guests can make reservations for available experiences by calling (407) 939-6690, or (800) 800-9800 for Disney Vacation Club Members, beginning on June 30.
Dining reservations for Walt Disney World Resort hotel and theme park locations available during initial reopening may only be booked online during this time. Reservations will not be available through the My Disney Experience app during this advance window. Discover which
dining locations and
experiences will be available during initial reopening.