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