Apex domains cannot have CNAME records.
Question and response
Question
dig nextlevelinternet.com. NS
Answer
nextlevelinternet.com. 5 NS auth3.nextlevelinternet.com.
nextlevelinternet.com. 5 NS auth2.nextlevelinternet.com.
nextlevelinternet.com. 5 NS auth1.nextlevelinternet.com.
nextlevelinternet.com. 5 NS auth4.nextlevelinternet.com.
Authority
The response has no authority records.
Additional
auth1.nextlevelinternet.com. 5 A 207.7.100.99
auth2.nextlevelinternet.com. 5 A 66.185.175.42
auth3.nextlevelinternet.com. 5 A 207.7.112.13
auth4.nextlevelinternet.com. 5 A 66.171.145.147
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0