Apex domains cannot have CNAME records.
Question and response
Question
dig az. NS
Answer
az. 5 NS ns3.intrans.az.
az. 5 NS ns13.intrans.az.
az. 5 NS az.hostmaster.ua.
az. 5 NS rip.psg.com.
Authority
The response has no authority records.
Additional
ns3.intrans.az. 171538 A 148.251.2.246
rip.psg.com. 2 A 147.28.0.39
ns13.intrans.az. 76636 A 217.14.111.13
ns3.intrans.az. 2 AAAA 2a01:4f8:201:52f3:0:0:0:3
rip.psg.com. 2 AAAA 2001:418:1:0:0:0:0:39
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0