Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-30.net. NS
Answer
awsdns-30.net. 5 NS g-ns-1374.awsdns-30.net.
awsdns-30.net. 5 NS g-ns-479.awsdns-30.net.
awsdns-30.net. 5 NS g-ns-800.awsdns-30.net.
awsdns-30.net. 5 NS g-ns-1950.awsdns-30.net.
Authority
The response has no authority records.
Additional
g-ns-479.awsdns-30.net. 5 A 205.251.193.223
g-ns-800.awsdns-30.net. 5 A 205.251.195.32
g-ns-1374.awsdns-30.net. 5 A 205.251.197.94
g-ns-1950.awsdns-30.net. 5 A 205.251.199.158
g-ns-479.awsdns-30.net. 5 AAAA 2600:9000:5301:df00:0:0:0:1
g-ns-800.awsdns-30.net. 5 AAAA 2600:9000:5303:2000:0:0:0:1
g-ns-1374.awsdns-30.net. 5 AAAA 2600:9000:5305:5e00:0:0:0:1
g-ns-1950.awsdns-30.net. 5 AAAA 2600:9000:5307:9e00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0