Local project operation

index.jsrequire('dotenv').config();
const express = require('express');
const mongoose = require('mongoose');
const { initiatePayment } = require('./piPayments');

const app = express();
const PORT = process.env.PORT || 3001;
const MONGODB_URI = process.env.MONGODB_URI;

mongoose.connect(MONGODB_URI, { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => console.log('Database connected'))
  .catch((err) => console.error('Database connection error:', err));

app.post('/api/pay', async (req, res) => {
  try {
    const payment = await initiatePayment(10, 'Test Payment');
    res.status(200).json(payment);
  } catch (error) {
    res.status(500).json({ error: 'Payment failed' });
  }
});

app.listen(PORT, () => console.log(`Backend running on http://localhost:${PORT}`));
Background.
cd backend
npm start
http://localhost:3001

piPayments.js:const { Pi } = require('@pihq/pi-node-sdk');

const pi = Pi.init({
  apiKey: process.env.PI_API_KEY,5d8bc63cfa473df9a90c3308432e255c892f4b363143dfd8fa98c6c44d1b0bda13b78ce5a9c195b1648220c33a7b4f026b8176c0a0c87ba421c309533a57480c
  sandbox: true,
});

async function initiatePayment(amount, memo) {
  try {
    const payment = await pi.createPayment({ amount, memo });
    return payment;
  } catch (error) {
    console.error('Payment initiation failed:', error);
  }
}

module.exports = { initiatePayment };


Front. 
cd frontend
npm start
http://localhost:3000