Legal provisions for mandatory referendums at national level

Syrian Arab Republic
Constitution,2012
https://www.constituteproject.org/constitution/Syria_2012.pdf
Article116
ThePresident of the Republic might call for a referendum on important issues whichaffect the higher interests of the country. The result of the referendum shallbe binding and come into force as of the date of its announcement; and it shallbe published by the President of the Republic.
Article148