Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-10.org. NS
Answer
awsdns-10.org. 5 NS g-ns-138.awsdns-10.org.
awsdns-10.org. 5 NS g-ns-1610.awsdns-10.org.
awsdns-10.org. 5 NS g-ns-1037.awsdns-10.org.
awsdns-10.org. 5 NS g-ns-716.awsdns-10.org.
Authority
The response has no authority records.
Additional
g-ns-138.awsdns-10.org. 5 A 205.251.192.138
g-ns-716.awsdns-10.org. 5 A 205.251.194.204
g-ns-1037.awsdns-10.org. 5 A 205.251.196.13
g-ns-1610.awsdns-10.org. 5 A 205.251.198.74
g-ns-138.awsdns-10.org. 5 AAAA 2600:9000:5300:8a00:0:0:0:1
g-ns-716.awsdns-10.org. 5 AAAA 2600:9000:5302:cc00:0:0:0:1
g-ns-1037.awsdns-10.org. 5 AAAA 2600:9000:5304:d00:0:0:0:1
g-ns-1610.awsdns-10.org. 5 AAAA 2600:9000:5306:4a00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0