Apex domains cannot have CNAME records.
Question and response
Question
dig microfinance.sn. NS
Answer
microfinance.sn. 4 NS dns17.ovh.net.
microfinance.sn. 4 NS ns17.ovh.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0