Presidential appointments
Section 171(4) · 1999 Constitution (2004 edition)
What Constitution says
(4) An appointment to the office of Ambassador, High Commissioner or other Principal Representative of Nigeria abroad shall not have effect unless the appointment is confirmed by the Senate.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 81. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections