Apex domains cannot have CNAME records.
Question and response
Question
dig adsl2.iam.net.ma. NS
Answer
adsl2.iam.net.ma. 5 NS dns2.menara.ma.
adsl2.iam.net.ma. 5 NS dns.menara.ma.
adsl2.iam.net.ma. 5 NS dns1.menara.ma.
adsl2.iam.net.ma. 5 NS dns3.menara.ma.
Authority
The response has no authority records.
Additional
dns.menara.ma. 5 A 81.192.21.33
dns1.menara.ma. 5 A 81.192.21.41
dns2.menara.ma. 5 A 81.192.21.65
dns3.menara.ma. 5 A 81.192.21.73
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0