Apex domains cannot have CNAME records.
Question and response
Question
dig supersaas.com. NS
Answer
supersaas.com. 2 NS ns-801.awsdns-36.net.
supersaas.com. 2 NS ns-1964.awsdns-53.co.uk.
supersaas.com. 2 NS ns-253.awsdns-31.com.
supersaas.com. 2 NS ns-1054.awsdns-03.org.
Authority
The response has no authority records.
Additional
ns-801.awsdns-36.net. 5 A 205.251.195.33
ns-1054.awsdns-03.org. 5 A 205.251.196.30
ns-1964.awsdns-53.co.uk. 5 A 205.251.199.172
ns-253.awsdns-31.com. 5 AAAA 2600:9000:5300:fd00:0:0:0:1
ns-801.awsdns-36.net. 5 AAAA 2600:9000:5303:2100:0:0:0:1
ns-1054.awsdns-03.org. 5 AAAA 2600:9000:5304:1e00:0:0:0:1
ns-1964.awsdns-53.co.uk. 5 AAAA 2600:9000:5307:ac00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0