Apex domains cannot have CNAME records.
Question and response
Question
dig betteruptime.com. NS
Answer
betteruptime.com. 5 NS keenan.ns.cloudflare.com.
betteruptime.com. 5 NS haley.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0