Apex domains cannot have CNAME records.
Question and response
Question
dig hostname.cl. NS
Answer
hostname.cl. 5 NS ns3.hostname.cl.
hostname.cl. 5 NS ns4.hostname.cl.
hostname.cl. 5 NS ns1.hostname.cl.
hostname.cl. 5 NS ns2.hostname.cl.
Authority
The response has no authority records.
Additional
ns1.hostname.cl. 5 A 201.159.174.100
ns2.hostname.cl. 5 A 64.120.17.98
ns3.hostname.cl. 5 A 190.110.120.101
ns4.hostname.cl. 5 A 190.110.120.100
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0