Apex domains cannot have CNAME records.
Question and response
Question
dig supportchat.uk. NS
Answer
supportchat.uk. 4 NS elmo.ns.cloudflare.com.
supportchat.uk. 4 NS mia.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0