Runner123 If you look at the detailed PDF e-Ticket for your ANA RTW trip you should see the Reservation Code which is the 6 digit alphanumeric code. For some reason, it was the same for all legs of my RTW trip EXCEPT for my 2 TK legs of the trip. So go review in the Remarks of your TK flight(s) and you will likely see a different 6 digit code which you can then use on that code on the Turkish website to manage your booking that way. For me, SQ used the same code as NK (as did AC) but you might double check that as well. Good luck!