Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-50.org. NS
Answer
awsdns-50.org. 5 NS g-ns-1077.awsdns-50.org.
awsdns-50.org. 5 NS g-ns-178.awsdns-50.org.
awsdns-50.org. 5 NS g-ns-756.awsdns-50.org.
awsdns-50.org. 5 NS g-ns-1650.awsdns-50.org.
Authority
The response has no authority records.
Additional
g-ns-178.awsdns-50.org. 5 A 205.251.192.178
g-ns-756.awsdns-50.org. 5 A 205.251.194.244
g-ns-1077.awsdns-50.org. 5 A 205.251.196.53
g-ns-1650.awsdns-50.org. 5 A 205.251.198.114
g-ns-178.awsdns-50.org. 5 AAAA 2600:9000:5300:b200:0:0:0:1
g-ns-756.awsdns-50.org. 5 AAAA 2600:9000:5302:f400:0:0:0:1
g-ns-1077.awsdns-50.org. 5 AAAA 2600:9000:5304:3500:0:0:0:1
g-ns-1650.awsdns-50.org. 5 AAAA 2600:9000:5306:7200:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0