Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-57.org. NS
Answer
awsdns-57.org. 5 NS g-ns-763.awsdns-57.org.
awsdns-57.org. 5 NS g-ns-1657.awsdns-57.org.
awsdns-57.org. 5 NS g-ns-185.awsdns-57.org.
awsdns-57.org. 5 NS g-ns-1084.awsdns-57.org.
Authority
The response has no authority records.
Additional
g-ns-185.awsdns-57.org. 5 A 205.251.192.185
g-ns-763.awsdns-57.org. 5 A 205.251.194.251
g-ns-1084.awsdns-57.org. 5 A 205.251.196.60
g-ns-1657.awsdns-57.org. 5 A 205.251.198.121
g-ns-185.awsdns-57.org. 5 AAAA 2600:9000:5300:b900:0:0:0:1
g-ns-763.awsdns-57.org. 5 AAAA 2600:9000:5302:fb00:0:0:0:1
g-ns-1084.awsdns-57.org. 5 AAAA 2600:9000:5304:3c00:0:0:0:1
g-ns-1657.awsdns-57.org. 5 AAAA 2600:9000:5306:7900:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0