Apex domains cannot have CNAME records.
Question and response
Question
dig 62-97-243.bkkb.no. NS
Answer
62-97-243.bkkb.no. 5 NS ns2.bkkb.no.
62-97-243.bkkb.no. 5 NS ns1.bkkb.no.
Authority
The response has no authority records.
Additional
ns1.bkkb.no. 5 A 62.97.193.3
ns2.bkkb.no. 5 A 62.97.193.53
ns1.bkkb.no. 5 AAAA 2a00:14d8:a:0:0:0:0:a
ns2.bkkb.no. 5 AAAA 2a00:14d8:b:0:0:0:0:b
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0