Apex domains cannot have CNAME records.
Question and response
Question
dig codetwo.com. NS
Answer
codetwo.com. 5 NS ns0.dnsmadeeasy.com.
codetwo.com. 5 NS ns3.dnsmadeeasy.com.
codetwo.com. 5 NS ns1.dnsmadeeasy.com.
codetwo.com. 5 NS ns2.dnsmadeeasy.com.
codetwo.com. 5 NS ns4.dnsmadeeasy.com.
Authority
The response has no authority records.
Additional
ns0.DNSMADEEASY.COM. 3 A 208.94.148.2
ns1.DNSMADEEASY.COM. 3 A 208.80.124.2
NS2.DNSMADEEASY.COM. 3 A 208.80.126.2
ns3.DNSMADEEASY.COM. 3 A 208.80.125.2
ns4.DNSMADEEASY.COM. 3 A 208.80.127.2
ns0.DNSMADEEASY.COM. 3 AAAA 2600:1800:0:0:0:0:0:1
ns1.DNSMADEEASY.COM. 3 AAAA 2600:1801:1:0:0:0:0:1
NS2.DNSMADEEASY.COM. 3 AAAA 2600:1802:2:0:0:0:0:1
ns3.DNSMADEEASY.COM. 3 AAAA 2600:1801:3:0:0:0:0:1
ns4.DNSMADEEASY.COM. 3 AAAA 2600:1802:4:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0