Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-05.com. NS
Answer
awsdns-05.com. 5 NS g-ns-1157.awsdns-05.com.
awsdns-05.com. 5 NS g-ns-1733.awsdns-05.com.
awsdns-05.com. 5 NS g-ns-6.awsdns-05.com.
awsdns-05.com. 5 NS g-ns-581.awsdns-05.com.
Authority
The response has no authority records.
Additional
g-ns-6.awsdns-05.com. 5 A 205.251.192.6
g-ns-581.awsdns-05.com. 5 A 205.251.194.69
g-ns-1157.awsdns-05.com. 5 A 205.251.196.133
g-ns-1733.awsdns-05.com. 5 A 205.251.198.197
g-ns-6.awsdns-05.com. 5 AAAA 2600:9000:5300:600:0:0:0:1
g-ns-581.awsdns-05.com. 5 AAAA 2600:9000:5302:4500:0:0:0:1
g-ns-1157.awsdns-05.com. 5 AAAA 2600:9000:5304:8500:0:0:0:1
g-ns-1733.awsdns-05.com. 5 AAAA 2600:9000:5306:c500:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0