server.py

@app.route('/create-checkout-session', methods=['POST'])
def create_checkout_session():
    try:
        checkout_session = stripe.checkout.Session.create(
            line_items=[
                {
                    'price': '<hard code your price ID here>',
                    'quantity': 1,
                },
            ],
            mode='subscription',
            success_url=YOUR_DOMAIN + '/success.html?session_id={CHECKOUT_SESSION_ID}',
            cancel_url=YOUR_DOMAIN + '/cancel.html',
        )
        return redirect(checkout_session.url, code=303)
    except Exception as e:
        print(e)
        return "Server error", 500