Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-43.org. NS
Answer
awsdns-43.org. 5 NS g-ns-1643.awsdns-43.org.
awsdns-43.org. 5 NS g-ns-1070.awsdns-43.org.
awsdns-43.org. 5 NS g-ns-171.awsdns-43.org.
awsdns-43.org. 5 NS g-ns-749.awsdns-43.org.
Authority
The response has no authority records.
Additional
g-ns-171.awsdns-43.org. 5 A 205.251.192.171
g-ns-749.awsdns-43.org. 5 A 205.251.194.237
g-ns-1070.awsdns-43.org. 5 A 205.251.196.46
g-ns-1643.awsdns-43.org. 5 A 205.251.198.107
g-ns-171.awsdns-43.org. 5 AAAA 2600:9000:5300:ab00:0:0:0:1
g-ns-749.awsdns-43.org. 5 AAAA 2600:9000:5302:ed00:0:0:0:1
g-ns-1070.awsdns-43.org. 5 AAAA 2600:9000:5304:2e00:0:0:0:1
g-ns-1643.awsdns-43.org. 5 AAAA 2600:9000:5306:6b00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0