app.js

const express = require('express');
const bodyParser = require('body-parser');
const request = require('request');
const https = require("https");

const app = express();

app.use(express.static("public"));
app.use(bodyParser.urlencoded({
    extended: true
}));

app.post('/', function (req, res) {
    var firstName = req.body.fName;
    var lastName = req.body.lName;
    var email = req.body.email;

    var data = {
        members: [{
            email_address: email,
            status: "subscribed",
            merge_fields: {
                FNAME: firstName,
                LNAME: lastName
            }
        }]
    }

    var jsonData = JSON.stringify(data);

    const url = "https://us18.api.mailchimp.com/3.0/lists/30bbe4a734 "

    const options = {
        method: "POST",
        auth: "apikey:50b873fd26a150cb263196c75176f9c7-us18"
    }

    const request = https.request(url, options, function (response) {
        if (response.statusCode === 200) {
            res.sendFile(__dirname + "/success.html")
        } else {
            res.sendFile(__dirname + "/failure.html")
        }
        response.on("data", function (data) {
            console.log(JSON.parse(data));
        })
    })
    request.write(jsonData);
    request.end();
});

app.post("/failure", function (req, res) {
    res.redirect('/')
})

app.get('/', function (req, res) {
    res.sendFile(__dirname + "/signup.html");
})

app.listen(process.env.PORT || 3000, function () {
    console.log("server is running on port 3000");
})