Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-63.org. NS
Answer
awsdns-63.org. 5 NS g-ns-1663.awsdns-63.org.
awsdns-63.org. 5 NS g-ns-1283.awsdns-63.org.
awsdns-63.org. 5 NS g-ns-191.awsdns-63.org.
awsdns-63.org. 5 NS g-ns-962.awsdns-63.org.
Authority
The response has no authority records.
Additional
g-ns-191.awsdns-63.org. 5 A 205.251.192.191
g-ns-962.awsdns-63.org. 5 A 205.251.195.194
g-ns-1283.awsdns-63.org. 5 A 205.251.197.3
g-ns-1663.awsdns-63.org. 5 A 205.251.198.127
g-ns-191.awsdns-63.org. 5 AAAA 2600:9000:5300:bf00:0:0:0:1
g-ns-962.awsdns-63.org. 5 AAAA 2600:9000:5303:c200:0:0:0:1
g-ns-1283.awsdns-63.org. 5 AAAA 2600:9000:5305:300:0:0:0:1
g-ns-1663.awsdns-63.org. 5 AAAA 2600:9000:5306:7f00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0