Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-03.com. NS
Answer
awsdns-03.com. 5 NS g-ns-4.awsdns-03.com.
awsdns-03.com. 5 NS g-ns-1731.awsdns-03.com.
awsdns-03.com. 5 NS g-ns-1155.awsdns-03.com.
awsdns-03.com. 5 NS g-ns-579.awsdns-03.com.
Authority
The response has no authority records.
Additional
g-ns-4.awsdns-03.com. 5 A 205.251.192.4
g-ns-579.awsdns-03.com. 5 A 205.251.194.67
g-ns-1155.awsdns-03.com. 5 A 205.251.196.131
g-ns-1731.awsdns-03.com. 5 A 205.251.198.195
g-ns-4.awsdns-03.com. 5 AAAA 2600:9000:5300:400:0:0:0:1
g-ns-579.awsdns-03.com. 5 AAAA 2600:9000:5302:4300:0:0:0:1
g-ns-1155.awsdns-03.com. 5 AAAA 2600:9000:5304:8300:0:0:0:1
g-ns-1731.awsdns-03.com. 5 AAAA 2600:9000:5306:c300:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0