No problem. Just to mention although no charge to change, any price increase does have to be paid
See below from TA site from various places
We are happy to offer you flexible travel opportunities as we know how difficult it is to plan in this period. Passengers can make unlimited changes for ticketings made between March 21, 2020 and August 31, 2020. Please review our Flexible Changing Rights page for more details.
As we return to the skies, we offer unlimited changing rights to ensure that our passengers enjoy maximum peace of mind. Flexible Travel opportunities are offered until the end of 2021 for tickets bought until August 31, 2020 (inclusive).
Terms and Conditions
No matter how many times your plans change, you are safe with Flexible Travel. Please review the terms and conditions to find out how Flexible Travel works!
A ticket change can be made for a different destination, provided that the fare difference is paid.
Change requests can be performed through the Turkish Airlines sales offices, call center, online channels (for international flight tickets only) and the agencies from which the ticket was purchased.
Passengers can make unlimited changes for ticketing made between March 21, 2020 and August 31, 2020.
In order to change the ticket to an Open Ticket, the reservation must be cancelled before the date of flight.
In order to change the ticket to an Open Ticket, cancellations must be performed via the Turkish Airlines call center, sales offices, or the agencies from which the ticket was purchased.
Fare differences incurred by taxes, exchange rates or fare class differences will be applied.