Ditto . Found though need to test just before marking as can emit too much paint
or if it's brand new no paint!
Before EACH use, shake well and then press the nib straight down onto a (sacrificial) hard surface.
This will release a drop of the paint.
Then you can 'paint' the liquid (no pressure required) onto Q.
And very very very importantly - give it time to dry before releasing Q. If you release her while it is still wet, it will wipe off, or be cleaned off by workers -- leaving you with a very indistinct marking, which defeats the object of the exercise.
Be brave, let the stuff dry properly!
And on eBay you can find economical supplies of all the colours Posca make, so you can choose a nice bright version, and a non-standard colour for practicing on Drones without confusing the issue!
Among the range of Posca pen
types, it is the "bullet pointed" PC-3M that is generally favoured for Q marking.