Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-22.com. NS
Answer
awsdns-22.com. 5 NS g-ns-1174.awsdns-22.com.
awsdns-22.com. 5 NS g-ns-23.awsdns-22.com.
awsdns-22.com. 5 NS g-ns-598.awsdns-22.com.
awsdns-22.com. 5 NS g-ns-1750.awsdns-22.com.
Authority
The response has no authority records.
Additional
g-ns-23.awsdns-22.com. 5 A 205.251.192.23
g-ns-598.awsdns-22.com. 5 A 205.251.194.86
g-ns-1174.awsdns-22.com. 5 A 205.251.196.150
g-ns-1750.awsdns-22.com. 5 A 205.251.198.214
g-ns-23.awsdns-22.com. 5 AAAA 2600:9000:5300:1700:0:0:0:1
g-ns-598.awsdns-22.com. 5 AAAA 2600:9000:5302:5600:0:0:0:1
g-ns-1174.awsdns-22.com. 5 AAAA 2600:9000:5304:9600:0:0:0:1
g-ns-1750.awsdns-22.com. 5 AAAA 2600:9000:5306:d600:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0