Colombia, national Agenda (setting) initiative [PAX] - Iniciativa popular (nacional)

Article 155.
Legislative bills or those involving constitutional amendments may be introduced by a number of citizens equal to or greater than five percent of the existing electoral rolls on the relevant date or by 30 percent of the councillors or deputies of the country. The popular initiative will be executed by the Congress, in accordance with the provisions in Article 163 with respect to bills that have been the subject of a declaration of urgency.
The proposing citizens shall have the right to designate a spokesman who shall be heard by the Houses at all stages of the proceedings.

Reference: Constititution of Colombia, 1991, (accessed 29.09.2021)

To propose a bill. A proposal of a constitutional amendment bill is possible as well.See also the possibility of a referendum following an agenda initiative for a constitutional amendment (ATP).