Student or Learner
Please fasten/Tighten the whiteboard in the way that it does not fall.
Does my sentence sound correct?
But tighten is a strange word to use. You tighten the screws that hold the whiteboard to the wall, but you don't 'tighten' the whiteboard. I would expect to see something like 'Make sure the whiteboard is fixed firmly [to the wall]'.
Please hang the whiteboard on the wall in such a way that it does not fall down.