Eveyone here is correct, just takes some stout down force.
I will add that those lift arms are screwed into some rather flimsey wood on the bed base and after a while may rip out some wood as you close it down. Not the end of the world, it's just wood and wood repairs easily compared to many other materials.
Region 3 , 1st VP
Go often to the house of a friend, for weeds choke the unused path........Emerson
Never pick a fight with an old man. If he is too old to fight he will just kill you........a wise old man.