Alma 31:14

Therefore, whosoever desired to worship, must go forth and stand upon the top thereof, and stretch forth his hands towards heaven, and cry with a loud voice, saying:

So whoever wanted to worship had to go up and stand on top of it. They stretched out their hands toward heaven and cried with a loud voice, saying:

When someone wanted to worship, they climbed up to the top of this platform, stretched their hands toward heaven, and shouted out a prayer: