Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-48.net. NS
Answer
awsdns-48.net. 5 NS g-ns-1968.awsdns-48.net.
awsdns-48.net. 5 NS g-ns-497.awsdns-48.net.
awsdns-48.net. 5 NS g-ns-818.awsdns-48.net.
awsdns-48.net. 5 NS g-ns-1392.awsdns-48.net.
Authority
The response has no authority records.
Additional
g-ns-497.awsdns-48.net. 5 A 205.251.193.241
g-ns-818.awsdns-48.net. 5 A 205.251.195.50
g-ns-1392.awsdns-48.net. 5 A 205.251.197.112
g-ns-1968.awsdns-48.net. 5 A 205.251.199.176
g-ns-497.awsdns-48.net. 5 AAAA 2600:9000:5301:f100:0:0:0:1
g-ns-818.awsdns-48.net. 5 AAAA 2600:9000:5303:3200:0:0:0:1
g-ns-1392.awsdns-48.net. 5 AAAA 2600:9000:5305:7000:0:0:0:1
g-ns-1968.awsdns-48.net. 5 AAAA 2600:9000:5307:b000:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0