I could only see it being a couple of things, if you hit the button and it doesn't squirt water but the wipers turn on your switch is most likely good.
Question, does the water pump turn on. Typically you can hear a whine or electronic motor sound. If you don't hear that then most likely the pump is either bad or not getting electricity. There are three fuses for the Wiper system, I don't see one that is listed for just the windshield fluid pump. Perhaps one of the wiper fuses is linked to that. The fuses are 11, 16, and 27 in the glove compartment fusebox. Refer to your manual on how to get to those fuses if you do not know how.
If the fuses are all good then perhaps you just have a dead pump. It is buried somewhere in front of the front drivers side wheel.
Good news is that the replacement of the pump is not that difficult looking. You remove the wheel and the wheel well shroud at the front/drivers side and it is right there. Here are the replacement instructions:
The part looks to be around $70 on Realoem.com, #14 in the list. The repair instructions above indicate that there are two different pumps for the windshield and the head lamps. I don't know if you have a headlamp cleaner as it shows optional, so I believe that the pump below is the correct one for you! You would need to verify.
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