Easy Chair Long Screw needs to be tight
That's a Poang.

The longer bolts (not screws) need a nut that has probably fallen out and got kicked under the sofa



The shorter bolts, used at the top of the armrest, probably screw into a threaded insert.



If this is problematic you can probably fit a T-nut (likely to be a metric thread)



While you are fixing this, you should tighten up the other bolts (as Ikea advise you to do periodically) or apply some non-permanent thread-lock fluid.



I have a couple of Poang disassembled in my garage, so I may be able to find out more later.