Javascript – Trouble sending request body in webhook end-point for stripe

Here’s the flow:

• Hit the stripe checkout end-point
• If the payment was successful, send an email to user

Email includes:

• Customer Name
• Starting date
• Ending date

So, far I’m able to hit the stripe checkout end-point then redirecting the user to that page and make the payment. But, I’m unable to pass the parameters that are required in the email to be sent.

Stripe Function

app.post('/stripe-checkout', async (req, res) => {
    try {
        let baseUrl = req.query.env == 'prod' ? 'https://leaf-for-business.web.app' : 'http://localhost:8080';
        const session = await stripe.checkout.sessions.create({
            line_items: [
                {
                    price_data: {
                        currency: 'usd',
                        product_data: {
                            name: 'Promotion Payment',
                        },
                        unit_amount: req.query.amount * 100, /// 1USD = 100 Cents
                    },
                    quantity: 1,
                }
            ],
            mode: 'payment',
            payment_method_types: [ "card" ],
            success_url: baseUrl + '/home',
        });

        res.send({
            success: true,
            session_id: session.id,
            redirect_url: session.url,
        });

    } catch (error) {
        res.status(404).send({
            success: false,
            error: error.message,
        });
    }
});

Webhook Function

app.post('/webhook', (request, response) => {
    const sig = request.headers['stripe-signature'];

    const endpointSecret = process.env.WEBHOOK_SECRET;
    let event;

    try {
        event = stripe.webhooks.constructEvent(request.body, sig, endpointSecret);
    } catch (err) {
        response.status(400).send(`Webhook Error: ${err.message}`);
        return;
    }

    // Handle the event
    switch (event.type) {
        case 'checkout.session.completed':
            const checkoutSessionCompleted = event.data.object;
            sendEmail(request.body); /// <<-- HERE'S THE PROBLEM
            break;
        default:
            console.log(`Unhandled event type ${event.type}`);
    }

    // Return a 200 response to acknowledge receipt of the event
    response.send();
});

Email Send

async function sendEmail(body) {
    const DOMAIN = "app.joinleaf.com";
    const SENDER_EMAIL = "[email protected]";

    const mailgun = new Mailgun(formData);
    const mg = mailgun.client({
        username: 'api',
        key: process.env.MG_PRIVATE_KEY,
        host: "api.eu.mailgun.net",
    });

    const customerEmail = body.email;
    const customerName = body.customer_name;

    //
    const startDate = body.start_date;
    const endDate = body.end_date;

    const emailBody = fs.readFileSync('src/email.html', 'utf8').toString();
    const finalTemp = emailBody.replaceAll('customer-name', customerName)
        .replace('start-date', startDate)
        .replace('end-date', endDate);

    const messageData = {
        from: SENDER_EMAIL,
        // to: [customerEmail, "[email protected]"],
        to: [customerEmail, "[email protected]"],
        // bcc: ["getleaflets.co"],
        subject: "Thank you for your purchase.",
        html: finalTemp,
    };

    const resp = await mg.messages.create(DOMAIN, messageData, (err, body) => {
        if (!err) {
            console.log('Sent! ' + body);
        } else {
            console.log(err);
        }
    });

    return resp;
}

Now, how can I send the name, start and end date to webhook so that it can be passed to email function if the payment is a success