Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-11.com. NS
Answer
awsdns-11.com. 5 NS g-ns-587.awsdns-11.com.
awsdns-11.com. 5 NS g-ns-12.awsdns-11.com.
awsdns-11.com. 5 NS g-ns-1739.awsdns-11.com.
awsdns-11.com. 5 NS g-ns-1163.awsdns-11.com.
Authority
The response has no authority records.
Additional
g-ns-12.awsdns-11.com. 5 A 205.251.192.12
g-ns-587.awsdns-11.com. 5 A 205.251.194.75
g-ns-1163.awsdns-11.com. 5 A 205.251.196.139
g-ns-1739.awsdns-11.com. 5 A 205.251.198.203
g-ns-12.awsdns-11.com. 5 AAAA 2600:9000:5300:c00:0:0:0:1
g-ns-587.awsdns-11.com. 5 AAAA 2600:9000:5302:4b00:0:0:0:1
g-ns-1163.awsdns-11.com. 5 AAAA 2600:9000:5304:8b00:0:0:0:1
g-ns-1739.awsdns-11.com. 5 AAAA 2600:9000:5306:cb00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0