Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-39.org. NS
Answer
awsdns-39.org. 5 NS g-ns-745.awsdns-39.org.
awsdns-39.org. 5 NS g-ns-1639.awsdns-39.org.
awsdns-39.org. 5 NS g-ns-167.awsdns-39.org.
awsdns-39.org. 5 NS g-ns-1066.awsdns-39.org.
Authority
The response has no authority records.
Additional
g-ns-167.awsdns-39.org. 5 A 205.251.192.167
g-ns-745.awsdns-39.org. 5 A 205.251.194.233
g-ns-1066.awsdns-39.org. 5 A 205.251.196.42
g-ns-1639.awsdns-39.org. 5 A 205.251.198.103
g-ns-167.awsdns-39.org. 5 AAAA 2600:9000:5300:a700:0:0:0:1
g-ns-745.awsdns-39.org. 5 AAAA 2600:9000:5302:e900:0:0:0:1
g-ns-1066.awsdns-39.org. 5 AAAA 2600:9000:5304:2a00:0:0:0:1
g-ns-1639.awsdns-39.org. 5 AAAA 2600:9000:5306:6700:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0