How to export a JavaScript object using module.exports in an npm package?

I published an npm package. The directory structure is something like the following:

my-package
└── js/script.js
└── index.js

The js/script.js file contains an object that is the name of my library, lets say elephant. Something like this:

var elephant = {
    function_1: function() {
        ...
    },
    function_2: function() {
        ...
    }
}

In my index.js file, I am exporting this like so:

import { elephant } from "./js/script.js";

module.exports = elephant;

Once I published and installed my package, I tried to pull it in my project using the following line of code:

const elephant = require('my-package');
elephant.function_1();
elephant.function_2();

However, unfortunately when I run my server (in a Vue project), I get the following error:

Uncaught TypeError: Cannot assign to read only property 'exports' of object '#<Object>'

I assume this is referring to the third line in the index.js file. How can I fix this issue? How do I export my object variable and use it in my node project? Thanks for any help!