I have a contact form on my website that I created with Node.js. When I run the site as a local host (localhost:5000), everything works fine. I fill out the contact form and when I hit send, I get a thank you alert and the email goes through.

However, once I connected my site to a domain and had it live, it no longer works - I get the "invalid login" message. I wrote an "if statement" in JS to return this "invalid login" error if the request does not go through, which is what I keep getting.

Could it be that I am not connecting to the correct server?

I'm guessing the xhr variable I use in my code is not valid once I begin using an actual hosting service. If so, how can I fix that?

Here is my code.

form.addEventListener('submit', (e)=>{
e.preventDefault();
console.log('submit clicked')

let formData = {
    email: email.value,
    level: password.value,
    amount: amount.value,
    service: service.value,
    details: details.value,
    email: email.value
}

let xhr = new XMLHttpRequest();
xhr.open('POST', '/');
xhr.setRequestHeader('content-type', 'application/json');
xhr.onload = function() {
    console.log(xhr.responseText);

    if (xhr.responseText == 'success'){
        alert('Thank you! An Ogma representative will contact you shortly.');
        email.value = '';
        password.value = '';
        amount.value = '';
        service.value = '';
        details.value = '';
        email.value = '';
    }else{
        alert('Invalid login')
    }

}

xhr.send(JSON.stringify(formData));


})

Edit: Here is my code with nodemailer. It is my Server.js file.

const express = require('express');
const app = express();

const nodemailer = require("nodemailer");

const PORT = process.env.PORT || 5000;

//Middleware
app.use(express.static('public'));
app.use(express.json())

app.get('/', (req, res)=>{
    res.sendFile(__dirname + '/public/Request.html')
})

app.post('/', (req, res)=>{
    console.log(req.body);

    const transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
            user: '//kept hidden',
            pass: //kept hidden 
        }
    })

    const mailOptions = {
        from: req.body.email,
        to: '//kept hidden',
        subject: 'New message from Ogma',
        text: [req.body.email, req.body.password, req.body.amount, `req.body.service, req.body.details].join('\n\n')`
    }

    transporter.sendMail(mailOptions, (error, info) =>{ 
        if(error){
            console.log(error);
            res.send('error');
        } else {
            console.log('Email sent: ' + info.response);
            res.send('success')
        }
    })
})


app.listen(PORT, ()=>{
    console.log('Server running on port ${PORT}')
})