Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-63.net. NS
Answer
awsdns-63.net. 5 NS g-ns-1407.awsdns-63.net.
awsdns-63.net. 5 NS g-ns-193.awsdns-63.net.
awsdns-63.net. 5 NS g-ns-514.awsdns-63.net.
awsdns-63.net. 5 NS g-ns-1983.awsdns-63.net.
Authority
The response has no authority records.
Additional
g-ns-193.awsdns-63.net. 5 A 205.251.192.193
g-ns-514.awsdns-63.net. 5 A 205.251.194.2
g-ns-1407.awsdns-63.net. 5 A 205.251.197.127
g-ns-1983.awsdns-63.net. 5 A 205.251.199.191
g-ns-193.awsdns-63.net. 5 AAAA 2600:9000:5300:c100:0:0:0:1
g-ns-514.awsdns-63.net. 5 AAAA 2600:9000:5302:200:0:0:0:1
g-ns-1407.awsdns-63.net. 5 AAAA 2600:9000:5305:7f00:0:0:0:1
g-ns-1983.awsdns-63.net. 5 AAAA 2600:9000:5307:bf00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0