Apex domains cannot have CNAME records.
Question and response
Question
dig guneydogutelekom.com.tr. NS
Answer
guneydogutelekom.com.tr. 3 NS ns2.ihsdnsx49.com.
guneydogutelekom.com.tr. 3 NS ns1.ihsdnsx49.com.
Authority
The response has no authority records.
Additional
ns1.ihsdnsx49.com. 5 A 94.138.199.222
ns1.ihsdnsx49.com. 5 A 185.216.113.50
ns1.ihsdnsx49.com. 5 A 185.216.113.51
ns2.ihsdnsx49.com. 5 A 185.216.113.51
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0