toshiba laptop print screen button not working

Without a clue as to the model or age of your laptop, it's going to be hard for anyone to help.

A link to the manufacturer's driver page may also be useful.

If your laptop is older, then you may simply have a mechanical keyboard problem.

Do you have the option to try with a different keyboard?

If no luck with the key,
Win SHIFT S presents snip and sketch options including full screen capture, for example.

You need to explain how you are using it ... PrtSc only, Fn+PrtSc, Alt+PrtSc, (whatever other key)+PrtSc ... ?

What happens with an external keyboard where the PrtSc key which functions independently ?

Print Screen key looks like it does nothing after pushing it, until you open up Paint and go to File/Paste.
As stated, press Win + Shift + S key to open Snipping tool.