Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-42.org. NS
Answer
awsdns-42.org. 5 NS g-ns-748.awsdns-42.org.
awsdns-42.org. 5 NS g-ns-1069.awsdns-42.org.
awsdns-42.org. 5 NS g-ns-1642.awsdns-42.org.
awsdns-42.org. 5 NS g-ns-170.awsdns-42.org.
Authority
The response has no authority records.
Additional
g-ns-170.awsdns-42.org. 5 A 205.251.192.170
g-ns-748.awsdns-42.org. 5 A 205.251.194.236
g-ns-1069.awsdns-42.org. 5 A 205.251.196.45
g-ns-1642.awsdns-42.org. 5 A 205.251.198.106
g-ns-170.awsdns-42.org. 5 AAAA 2600:9000:5300:aa00:0:0:0:1
g-ns-748.awsdns-42.org. 5 AAAA 2600:9000:5302:ec00:0:0:0:1
g-ns-1069.awsdns-42.org. 5 AAAA 2600:9000:5304:2d00:0:0:0:1
g-ns-1642.awsdns-42.org. 5 AAAA 2600:9000:5306:6a00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0