Apex domains cannot have CNAME records.
Question and response
Question
dig terra.net.lb. NS
Answer
terra.net.lb. 5 NS ans3.terra.net.lb.
terra.net.lb. 5 NS ns2.terra.net.lb.
terra.net.lb. 5 NS ns1.terra.net.lb.
Authority
The response has no authority records.
Additional
ns1.terra.net.lb. 5 A 212.98.130.34
ns2.terra.net.lb. 5 A 212.98.130.35
ans3.terra.net.lb. 5 A 134.119.216.54
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0