According to
Delta Flight Change Policy Customers traveling within the fifty United States, Puerto Rico, Canada, and the U.S. Virgin Islands do need to pay any fee for updating the flight. Still, they must remember the difference amount will be deposited to the airline if their new flight is more costly than their initial flight.
Terms And Conditions to Change Delta Airlines Flight
You must go through the crucial points as mentioned below before attempting to change the flight via Delta Airlines various portals such as mobile application, official site and Telephone number.
Source:
https://cancellationflights.com/blog/delta-flight-change-policy/
