Javascript – Move function to another js file

I am learning Javascript and Electron. The app has an entry point named ‘main.js’. I am just getting familiar with making calls to an API, so the scripts at the moment are very basic and don’t have any frontend. Basically, I am logging in, getting some data and logging out. It all works fine when the functions are in main.js, but now I am trying to move one of the functions to a different .js file and, depending on whether I use the import or require keywords and syntax, I get either the ‘Cannot use import statement outside a module’ or the ‘xxx is not a function’ errors. I also tried to change the extension as ‘main.mjs’ (I read this in another post as a possible solution) but it does not work. Obviously, I’m doing something wrong, but I can’t understand what. Would anyone be so kind as to explain?

This is the code for ‘main.js’:

import auth from './auth.js';

// disable the server's self-signed certificate validation
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = '0'

const serviceLayer = 'https://xxx.xxx.xxx.xxx:50000/b1s/v1/'
const data = {
    "CompanyDB": "myDB",
    "UserName": "myUsername",
    "Password": "myPassword"
}

const login = async () => {
    try {
        const url = serviceLayer + 'Login'
        const customHeaders = {
            'Content-Type': "application/json",
        }

        const response = await fetch(url, {
            method: 'POST',
            headers: customHeaders,
            body: JSON.stringify(data),
            credentials: 'include' // include cookies in the request
        })

        const cookiesArray = response.headers.getSetCookie()
        const sessionId = cookiesArray[0].substring(10, 68)
        const node = cookiesArray[1].substring(8, 14)
        const cookies = {
            'B1SESSION': sessionId,
            'ROUTEID': node
        }

        return cookies
    } catch (error) {
        console.log(error);
    }
}

const getOwor = async (session, node, id) => {
    try {
        const url = serviceLayer + 'ProductionOrders(' + id + ')'
        const customHeaders = {
            'Content-Type': "application/json",
            'Cookie': "B1SESSION=" + session + ";ROUTEID=" + node
        }

        const response = await fetch(url, {
            method: 'GET',
            headers: customHeaders
        })

        const json = response.json()
        return json
    } catch (error) {
        console.log(error);
    }
}

(async function () {
    const cookies = await login();
    console.log(cookies)
    const owor = await getOwor(cookies['B1SESSION'], cookies['ROUTEID'], 87);
    console.log(owor)
    const logoutStatus = await auth.logout(cookies['B1SESSION'], cookies['ROUTEID']);
    console.log(logoutStatus)
    process.exit()
})()

This is the code for ‘auth.js’:

const logout = async (session, node) => {
    try {
        const url = serviceLayer + 'Logout'
        const customHeaders = {
            'Content-Type': "application/json",
            'Cookie': "B1SESSION=" + session + ";ROUTEID=" + node
        }

        const response = await fetch(url, {
            method: 'POST',
            headers: customHeaders,
            body: JSON.stringify(data)
        })

        const status = response.status
        return status
    } catch (error) {
        console.log(error);
    }
}

export default logout

And, finally, this is the error:

Uncaught Exception: C:……main.js:1
import auth from ‘./auth.js’;
Syntax error: Cannot use import statement outside a module