Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-12.org. NS
Answer
awsdns-12.org. 5 NS g-ns-1612.awsdns-12.org.
awsdns-12.org. 5 NS g-ns-140.awsdns-12.org.
awsdns-12.org. 5 NS g-ns-718.awsdns-12.org.
awsdns-12.org. 5 NS g-ns-1039.awsdns-12.org.
Authority
The response has no authority records.
Additional
g-ns-140.awsdns-12.org. 5 A 205.251.192.140
g-ns-718.awsdns-12.org. 5 A 205.251.194.206
g-ns-1039.awsdns-12.org. 5 A 205.251.196.15
g-ns-1612.awsdns-12.org. 5 A 205.251.198.76
g-ns-140.awsdns-12.org. 5 AAAA 2600:9000:5300:8c00:0:0:0:1
g-ns-718.awsdns-12.org. 5 AAAA 2600:9000:5302:ce00:0:0:0:1
g-ns-1039.awsdns-12.org. 5 AAAA 2600:9000:5304:f00:0:0:0:1
g-ns-1612.awsdns-12.org. 5 AAAA 2600:9000:5306:4c00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0