1. Firebase Realtime Database:

   - Go to the [Firebase console](https://console.firebase.google.com/).

   - Select your project or create a new one.

   - Click on the Realtime Database section and set up your database.

   - Make sure you have data in your database to transfer.

   - Go to Project Settings > Service Accounts > Firebase Admin SDK and generate a new private key. This will download a JSON file with your service account credentials.

2. Google Sheets:

   - Create a new Google Sheet where you want to import your Firebase data.

   - Note down the Sheet ID from the URL (e.g., `https://docs.google.com/spreadsheets/d/``Sheet_ID``/edit`).

1. In your Google Sheet, click on `Extensions` > `Apps Script`.

2. This will open a new tab with the Apps Script editor.

1. In the Apps Script editor, go to `Resources` > `Advanced Google services`.

2. Scroll down and enable the `Google Sheets API`.

3. Click on the `+` next to `Services` to add a new service.

4. Search for and add the `Admin SDK`.

1. In the Apps Script editor, replace the existing content with the following code:

```javascript

const sheetId = 'YOUR_GOOGLE_SHEET_ID'; // Replace with your Google Sheet ID

const firebaseUrl = 'YOUR_FIREBASE_DATABASE_URL'; // Replace with your Firebase Database URL

const privateKey = '-----BEGIN PRIVATE KEY-----\n...\n-----END PRIVATE KEY-----\n'; // Replace with your private key from the JSON file

const clientEmail = 'your-service-account-email@...gserviceaccount.com'; // Replace with your service account email from the JSON file

function importDataFromFirebase() {

  const options = {

    method: 'GET',

    headers: {

      'Content-Type': 'application/json',

      'Authorization': 'Bearer ' + getFirebaseAccessToken(privateKey, clientEmail)

    }

  };

  const response = UrlFetchApp.fetch(firebaseUrl + '.json', options);

  const data = JSON.parse(response.getContentText());

  writeToSheet(data);

}

function getFirebaseAccessToken(privateKey, clientEmail) {

  const tokenUrl = 'https://accounts.google.com/o/oauth2/token';

  const tokenPayload = {

    grant_type: 'urn:ietf:params:oauth:grant-type:jwt-bearer',

    assertion: createJwt(privateKey, clientEmail)

  };

  const tokenOptions = {

    method: 'post',

    contentType: 'application/x-www-form-urlencoded',

    payload: tokenPayload

  };

  const response = UrlFetchApp.fetch(tokenUrl, tokenOptions);

  const accessToken = JSON.parse(response.getContentText()).access_token;

  return accessToken;

}

function createJwt(privateKey, clientEmail) {

  const header = {

    alg: 'RS256',

    typ: 'JWT'

  };

  const now = Math.floor(Date.now() / 1000);

  const claimSet = {

    iss: clientEmail,

    scope: 'https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email',

    aud: 'https://accounts.google.com/o/oauth2/token',

    exp: now + 3600,

    iat: now

  };

  const base64Header = Utilities.base64EncodeWebSafe(JSON.stringify(header));

  const base64ClaimSet = Utilities.base64EncodeWebSafe(JSON.stringify(claimSet));

  const signatureInput = `${base64Header}.${base64ClaimSet}`;

  const signature = Utilities.computeRsaSha256Signature(signatureInput, privateKey);

  const base64Signature = Utilities.base64EncodeWebSafe(signature);

  return `${signatureInput}.${base64Signature}`;

}

function writeToSheet(data) {

  const sheet = SpreadsheetApp.openById(sheetId).getActiveSheet();

  const rows = [];

  // Assuming data is an object where keys are the record IDs

  for (const id in data) {

    const record = data[id];

    // Assuming each record is an object with properties you want to extract

    rows.push([id, record.property1, record.property2]); // Replace with actual property names

  }

  // Clear existing content

  sheet.clearContents();

  // Assuming the first row contains headers

  const headers = ['ID', 'Property 1', 'Property 2']; // Replace with actual headers

  sheet.appendRow(headers);

  // Append new rows to the sheet

  rows.forEach(row => sheet.appendRow(row));

}

```

2. Replace the placeholders (`YOUR_GOOGLE_SHEET_ID`, `YOUR_FIREBASE_DATABASE_URL`, `privateKey`, and `clientEmail`) with your actual Google Sheet ID, Firebase Database URL, and the service account details you obtained earlier.

1. Click on the play button (`▶`) in the Apps Script toolbar to run the `importDataFromFirebase` function.

2. The script will request authorization the first time you run it. Follow the prompts to grant the necessary permissions.

3. Once the script has completed, your Google Sheet should be populated with data from your Firebase Realtime Database.

If you want to automatically update the Google Sheet with Firebase data at regular intervals:

1. In the Apps Script editor, click on the clock icon (`⏲`) to open the `Triggers` page.

2. Click `+ Add Trigger` in the bottom right corner.

3. Set up the trigger for the `importDataFromFirebase` function, choosing the frequency with which you want the script to run.