Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-53.org. NS
Answer
awsdns-53.org. 5 NS g-ns-759.awsdns-53.org.
awsdns-53.org. 5 NS g-ns-1080.awsdns-53.org.
awsdns-53.org. 5 NS g-ns-1653.awsdns-53.org.
awsdns-53.org. 5 NS g-ns-181.awsdns-53.org.
Authority
The response has no authority records.
Additional
g-ns-181.awsdns-53.org. 5 A 205.251.192.181
g-ns-759.awsdns-53.org. 5 A 205.251.194.247
g-ns-1080.awsdns-53.org. 5 A 205.251.196.56
g-ns-1653.awsdns-53.org. 5 A 205.251.198.117
g-ns-181.awsdns-53.org. 5 AAAA 2600:9000:5300:b500:0:0:0:1
g-ns-759.awsdns-53.org. 5 AAAA 2600:9000:5302:f700:0:0:0:1
g-ns-1080.awsdns-53.org. 5 AAAA 2600:9000:5304:3800:0:0:0:1
g-ns-1653.awsdns-53.org. 5 AAAA 2600:9000:5306:7500:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0