what is the process for getting Referendums on ballots

I presume this is for the Annual Meeting of Members. Like publicly traded corporations, I think any member/shareholder can request a referendum, following any procedure available for doing so. Notably there are "notice" requirements for Annual Meetings, so one should meet these requirements first. The board should have the referendum item placed on the agenda and should hold a legal vote for it. In my roughly 20 years with HOAs, I do not think I have ever seen a member ask for an item to be put on the agenda and voted on for the annual meeting. I think this is partly because many members are under the mistaken belief that votes may be held spontaneously at the annual meeting. Nor should any official business be discussed at the annual meeting that is not on the agenda, due to notice requirements. If people want to talk about something not on the agenda, they should wait until after the annual meeting has concluded, asking people to stick around.