Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-23.net. NS
Answer
awsdns-23.net. 5 NS g-ns-793.awsdns-23.net.
awsdns-23.net. 5 NS g-ns-1367.awsdns-23.net.
awsdns-23.net. 5 NS g-ns-1943.awsdns-23.net.
awsdns-23.net. 5 NS g-ns-472.awsdns-23.net.
Authority
The response has no authority records.
Additional
g-ns-472.awsdns-23.net. 5 A 205.251.193.216
g-ns-793.awsdns-23.net. 5 A 205.251.195.25
g-ns-1367.awsdns-23.net. 5 A 205.251.197.87
g-ns-1943.awsdns-23.net. 5 A 205.251.199.151
g-ns-472.awsdns-23.net. 5 AAAA 2600:9000:5301:d800:0:0:0:1
g-ns-793.awsdns-23.net. 5 AAAA 2600:9000:5303:1900:0:0:0:1
g-ns-1367.awsdns-23.net. 5 AAAA 2600:9000:5305:5700:0:0:0:1
g-ns-1943.awsdns-23.net. 5 AAAA 2600:9000:5307:9700:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0