Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-37.net. NS
Answer
awsdns-37.net. 5 NS g-ns-486.awsdns-37.net.
awsdns-37.net. 5 NS g-ns-807.awsdns-37.net.
awsdns-37.net. 5 NS g-ns-1381.awsdns-37.net.
awsdns-37.net. 5 NS g-ns-1957.awsdns-37.net.
Authority
The response has no authority records.
Additional
g-ns-486.awsdns-37.net. 5 A 205.251.193.230
g-ns-807.awsdns-37.net. 5 A 205.251.195.39
g-ns-1381.awsdns-37.net. 5 A 205.251.197.101
g-ns-1957.awsdns-37.net. 5 A 205.251.199.165
g-ns-486.awsdns-37.net. 5 AAAA 2600:9000:5301:e600:0:0:0:1
g-ns-807.awsdns-37.net. 5 AAAA 2600:9000:5303:2700:0:0:0:1
g-ns-1381.awsdns-37.net. 5 AAAA 2600:9000:5305:6500:0:0:0:1
g-ns-1957.awsdns-37.net. 5 AAAA 2600:9000:5307:a500:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0