using Javascript in posts

Hello. I am trying to use a javascript that doesn’t use the standard sort of “onClick” functions. it is for a click-to-zoom pop up thing for images.

I tried a variety of things. But because there are several function references in the javascript file, I am unsure how to call them in the individual posts (as I’ve read is necessary).

I tried to write a function to call the entire javascript file for the individual post, but as I suspected, that didn’t work either. Is there anyway to do this?