Apex domains cannot have CNAME records.
Question and response
Question
dig nicosvalsamakis.com. NS
Answer
nicosvalsamakis.com. 1 NS ns3-21.azure-dns.org.
nicosvalsamakis.com. 1 NS ns1-21.azure-dns.com.
nicosvalsamakis.com. 1 NS ns2-21.azure-dns.net.
nicosvalsamakis.com. 1 NS ns4-21.azure-dns.info.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0