Who can initiate an optional referendum at the national level?

Morocco
Morocco’s Constitution of 2011
https://www.constituteproject.org/constitution/Morocco_2011.pdf
Article 172:
Theinitiative of the revision of the Constitution belongs to the King, to the Headof Government,and to the Chamber of Representatives and to the Chamber of Councillors.
The King cansubmit directly to referendum the bill of revision of which He takes the Initiative.