Duties of the citizen
Section 24(b) · 1999 Constitution (2004 edition)
What Constitution says
(b) help to enhance the power, prestige and good name of Nigeria, defend Nigeria and render such national service as may be required;
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 30. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections