Electron error "is not a function" when using a function from a different JS file

Question

I am trying to create my first electron app.

I have a function in a JavaScript file (OtherFile.js):

function initializeOther() {
 ...
}

In my main JavaScript file I have

const { initializeOther} = require('./ioadapters/controllers/OtherFile');

function main() {
  initializeOther();
  app.on('ready', createWindow);
}

...

main();

I am trying to use the function from the other file. I only defined the function. I am not "exporting" it.

But I am getting following error:

App threw an error during load TypeError: initializeOther is not a function

What do I have to do to fix it?