Can you screed over chipboard?

No I would take the chipboard up or apply tiles to chipboard but don't screed the wood floor

The chipboard would brake up when it got wet . Best to tile over chipboard or best to take chipboard up then lay screed

Take up the chipboard then lay the screed

Simply put, no. Remove the chipboard before laying a screed. Additionally, I wouldn't ever lay tile directly onto chipboard because of the movement with temperature changes that would likely cause the tiles to crack.