Why Won’t My Keyboard Type an Apostrophe?

The apostrophe issue is most likely due to the keyboard settings on your computer's operating system. 

The keyboard on your OS needs to be set at US Standard and not US International.

On Mac, go to system preferences and click on Keyboard. There, go to Input Sources

Scroll to languages and click on languages and input settings.

Check the language you are using is the one you want (English).

On the right make sure the Input Method is US keyboard (standard) and not US International.

For Windows, every version has its nuances because they've changed how to reach the control panel. You can check out this (external) article for more information.