How do you fix a bathtub drain stopper?

How do you adjust a bathtub pop up drain stopper?

Why won’t my pop up plug stay down?

On the back of the drainpipe, there is a nut. … If the stopper moves as it should but doesn’t stay put, all you need to do is tighten the nut (turn it clockwise). If the action is too stiff, loosen the nut a little. Check the action and adjust until it feels about right.