Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-13.net. NS
Answer
awsdns-13.net. 5 NS g-ns-1357.awsdns-13.net.
awsdns-13.net. 5 NS g-ns-462.awsdns-13.net.
awsdns-13.net. 5 NS g-ns-783.awsdns-13.net.
awsdns-13.net. 5 NS g-ns-1933.awsdns-13.net.
Authority
The response has no authority records.
Additional
g-ns-462.awsdns-13.net. 5 A 205.251.193.206
g-ns-783.awsdns-13.net. 5 A 205.251.195.15
g-ns-1357.awsdns-13.net. 5 A 205.251.197.77
g-ns-1933.awsdns-13.net. 5 A 205.251.199.141
g-ns-462.awsdns-13.net. 5 AAAA 2600:9000:5301:ce00:0:0:0:1
g-ns-783.awsdns-13.net. 5 AAAA 2600:9000:5303:f00:0:0:0:1
g-ns-1357.awsdns-13.net. 5 AAAA 2600:9000:5305:4d00:0:0:0:1
g-ns-1933.awsdns-13.net. 5 AAAA 2600:9000:5307:8d00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0