Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-45.org. NS
Answer
awsdns-45.org. 5 NS g-ns-1645.awsdns-45.org.
awsdns-45.org. 5 NS g-ns-173.awsdns-45.org.
awsdns-45.org. 5 NS g-ns-751.awsdns-45.org.
awsdns-45.org. 5 NS g-ns-1072.awsdns-45.org.
Authority
The response has no authority records.
Additional
g-ns-173.awsdns-45.org. 5 A 205.251.192.173
g-ns-751.awsdns-45.org. 5 A 205.251.194.239
g-ns-1072.awsdns-45.org. 5 A 205.251.196.48
g-ns-1645.awsdns-45.org. 5 A 205.251.198.109
g-ns-173.awsdns-45.org. 5 AAAA 2600:9000:5300:ad00:0:0:0:1
g-ns-751.awsdns-45.org. 5 AAAA 2600:9000:5302:ef00:0:0:0:1
g-ns-1072.awsdns-45.org. 5 AAAA 2600:9000:5304:3000:0:0:0:1
g-ns-1645.awsdns-45.org. 5 AAAA 2600:9000:5306:6d00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0