Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-46.com. NS
Answer
awsdns-46.com. 5 NS g-ns-1198.awsdns-46.com.
awsdns-46.com. 5 NS g-ns-47.awsdns-46.com.
awsdns-46.com. 5 NS g-ns-622.awsdns-46.com.
awsdns-46.com. 5 NS g-ns-1774.awsdns-46.com.
Authority
The response has no authority records.
Additional
g-ns-47.awsdns-46.com. 5 A 205.251.192.47
g-ns-622.awsdns-46.com. 5 A 205.251.194.110
g-ns-1198.awsdns-46.com. 5 A 205.251.196.174
g-ns-1774.awsdns-46.com. 5 A 205.251.198.238
g-ns-47.awsdns-46.com. 5 AAAA 2600:9000:5300:2f00:0:0:0:1
g-ns-622.awsdns-46.com. 5 AAAA 2600:9000:5302:6e00:0:0:0:1
g-ns-1198.awsdns-46.com. 5 AAAA 2600:9000:5304:ae00:0:0:0:1
g-ns-1774.awsdns-46.com. 5 AAAA 2600:9000:5306:ee00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0