Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-22.org. NS
Answer
awsdns-22.org. 5 NS g-ns-150.awsdns-22.org.
awsdns-22.org. 5 NS g-ns-728.awsdns-22.org.
awsdns-22.org. 5 NS g-ns-1049.awsdns-22.org.
awsdns-22.org. 5 NS g-ns-1622.awsdns-22.org.
Authority
The response has no authority records.
Additional
g-ns-150.awsdns-22.org. 5 A 205.251.192.150
g-ns-728.awsdns-22.org. 5 A 205.251.194.216
g-ns-1049.awsdns-22.org. 5 A 205.251.196.25
g-ns-1622.awsdns-22.org. 5 A 205.251.198.86
g-ns-150.awsdns-22.org. 5 AAAA 2600:9000:5300:9600:0:0:0:1
g-ns-728.awsdns-22.org. 5 AAAA 2600:9000:5302:d800:0:0:0:1
g-ns-1049.awsdns-22.org. 5 AAAA 2600:9000:5304:1900:0:0:0:1
g-ns-1622.awsdns-22.org. 5 AAAA 2600:9000:5306:5600:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0