Steps to Create Server

//index.js

const express = require("express");
const mongoose = require("mongoose");
const cors = require("cors");

const app = express();
const PORT = process.env.PORT || 5000;
app.use(cors());

// Connect to MongoDB
mongoose.connect("<MONGODB_URL>", {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});

// Define a Donation schema
const donationSchema = new mongoose.Schema({
    name: { type: String, required: true },
    amount: { type: Number, required: true },
    description: { type: String, required: true },
});

const Donation = mongoose.model("Donation", donationSchema);

// Define a Total Amount schema
const totalAmountSchema = new mongoose.Schema({
    total: { type: Number, required: true },
    current: { type: Number, required: true },
});

const TotalAmount = mongoose.model("TotalAmount", totalAmountSchema);

// GET route to fetch total amount
app.get("/api/totalAmount", async (req, res) => {
    try {
        // Fetch total amount
        const totalAmount = await TotalAmount.findOne();
        res.json(totalAmount);
    } catch (error) {
        console.error(error);
        res.status(500).send("Internal Server Error");
    }
});

// PUT route to update current amount
app.put("/api/totalAmount", async (req, res) => {
    try {
        const { current } = req.body;

        // Update current amount
        const totalAmount = await TotalAmount.findOne();
        totalAmount.current = current;
        await totalAmount.save();

        res.status(200).send("Current amount updated successfully");
    } catch (error) {
        console.error(error);
        res.status(500).send("Internal Server Error");
    }
});

// API routes for donations
app.post("/api/donations", async (req, res) => {
    try {
        const { name, amount, description } = req.body;

        // Create a new donation
        const newDonation = new Donation({ name, amount, description });
        await newDonation.save();

        // Update the current total amount
        const totalAmount = await TotalAmount.findOne();
        totalAmount.current += amount;
        await totalAmount.save();

        res.status(201).json(newDonation);
    } catch (error) {
        console.error(error);
        res.status(500).send("Internal Server Error");
    }
});

app.get("/api/donations", async (req, res) => {
    try {
        // Fetch all donations
        const donations = await Donation.find();
        res.json(donations);
    } catch (error) {
        console.error(error);
        res.status(500).send("Internal Server Error");
    }
});

// Start the server
app.listen(PORT, () => {
    console.log(`Server is running on http://localhost:${PORT}`);
});