Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-04.com. NS
Answer
awsdns-04.com. 5 NS g-ns-5.awsdns-04.com.
awsdns-04.com. 5 NS g-ns-1732.awsdns-04.com.
awsdns-04.com. 5 NS g-ns-1156.awsdns-04.com.
awsdns-04.com. 5 NS g-ns-580.awsdns-04.com.
Authority
The response has no authority records.
Additional
g-ns-5.awsdns-04.com. 5 A 205.251.192.5
g-ns-580.awsdns-04.com. 5 A 205.251.194.68
g-ns-1156.awsdns-04.com. 5 A 205.251.196.132
g-ns-1732.awsdns-04.com. 5 A 205.251.198.196
g-ns-5.awsdns-04.com. 5 AAAA 2600:9000:5300:500:0:0:0:1
g-ns-580.awsdns-04.com. 5 AAAA 2600:9000:5302:4400:0:0:0:1
g-ns-1156.awsdns-04.com. 5 AAAA 2600:9000:5304:8400:0:0:0:1
g-ns-1732.awsdns-04.com. 5 AAAA 2600:9000:5306:c400:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0