1. Head over to the Firebase Console.
2. Click "Add Project" and just follow the steps to create a new Firebase project.
3. Once your project is up and running, add Firebase to the platforms you need (iOS, Android, web).

1. If you haven't already, install the Firebase CLI:
   ```bash
   npm install -g firebase-tools
   ```
2. Log in to Firebase from your terminal:
   ```bash
   firebase login
   ```
3. Initialize Firebase Functions in your project directory:
   ```bash
   firebase init functions
   ```

• Pick an existing Firebase project.
• Choose either JavaScript or TypeScript when asked about the language.
• Install dependencies if it asks you to.

Navigate to the functions directory:

cd functions

Install the necessary npm packages:

npm install firebase-admin firebase-functions nodemailer

Open index.js inside the functions folder and add this code:

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const nodemailer = require('nodemailer');

admin.initializeApp();

const transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: '[email protected]',
        pass: 'your-email-password'
    }
});

// Function to send email
exports.sendScheduledEmail = functions.pubsub.schedule('every 24 hours').onRun(async (context) => {
    const mailOptions = {
        from: '[email protected]',
        to: '[email protected]',
        subject: 'Scheduled Email',
        text: 'This is a scheduled email from Firebase Cloud Functions!'
    };
    
    try {
        await transporter.sendMail(mailOptions);
        console.log('Email successfully sent');
    } catch (error) {
        console.error('Error sending email:', error);
    }
});

Deploy the function to Firebase:

firebase deploy --only functions

Scheduled functions and email sending need a Blaze plan:

1. Go to the Firebase Console.
2. Head to your project settings under "Usage and billing".
3. Switch to the Blaze (pay-as-you-go) plan.

This step is super important because scheduled functions and external network requests (like sending emails via Gmail) are only available in the Blaze plan.

• Environment Variables: Store sensitive info like email credentials using environment configuration:
  ```bash
  firebase functions:config:set gmail.email="your-email@gmail.com" gmail.password="your-email-password"
  ```
  Then fetch them within your functions:
  ```javascript
  const gmailEmail = functions.config().gmail.email;
  const gmailPassword = functions.config().gmail.password;
  const transporter = nodemailer.createTransport({
  service: 'gmail',
  auth: {
  user: gmailEmail,
  pass: gmailPassword
  }
  });
  ```

• Testing: Before deploying, test your functions locally:
  ```bash
  firebase emulators:start --only functions
  ```