My directory is as such:

├Script.js
|
├public/
|     └...
└src/
   └ App.js

and inside App.js I'm trying to invoke the Script.js as such:

import calculations from './../Script' 

...

onclick={()=>{calculations()}}

Script.js:

const calculations=()=>{...}

export default calculations;

but obviously it won't work, so how do I run a script on the server?
do I make a post request to the server? If so, how do I handle it? (like in express app.post())