1. Head over to the Firebase Console.
2. Click on Add Project and just follow the steps to either create a new project or pick an existing one.
3. Once you're all set, go to the project dashboard.

1. In your Firebase project, click the </> icon to add Firebase to your web app.

2. Follow the instructions to grab the Firebase SDK and firebaseConfig object.

3. Add the script tags to your HTML and initialize Firebase with the firebaseConfig object at the start of your JavaScript file.

   ```javascript
   // Import the required Firebase modules
   import { initializeApp } from "https://www.gstatic.com/firebasejs/9.1.2/firebase-app.js";
   import { getMessaging, getToken, onMessage } from "https://www.gstatic.com/firebasejs/9.1.2/firebase-messaging.js";

   const firebaseConfig = {
   apiKey: "YOUR_API_KEY",
   authDomain: "YOUR_AUTH_DOMAIN",
   projectId: "YOUR_PROJECT_ID",
   storageBucket: "YOUR_STORAGE_BUCKET",
   messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
   appId: "YOUR_APP_ID",
   };

   // Initialize Firebase
   const app = initializeApp(firebaseConfig);
   ```

1. In the Firebase console, go to Project Settings.
2. Click on the Cloud Messaging tab.
3. Make sure the Cloud Messaging API is enabled and generate the Server Key. You'll need this for sending notifications.

1. Ask the user for notification permissions and get an FCM token.

   ```javascript
   const messaging = getMessaging(app);

   // Request permission to send notifications
   Notification.requestPermission().then((permission) => {
   if (permission === 'granted') {
   console.log('Notification permission granted.');
   getToken(messaging, { vapidKey: 'YOUR_PUBLIC_VAPID_KEY' }).then((currentToken) => {
   if (currentToken) {
   console.log('FCM Token:', currentToken);
   // Send the token to your server and subscribe to the topic
   subscribeToTopic(currentToken, 'news'); // Example topic: 'news'
   } else {
   console.log('No registration token available. Request permission to generate one.');
   }
   });
   } else {
   console.log('Unable to get permission to notify.');
   }
   });

   function subscribeToTopic(token, topic) {
   fetch(https://iid.googleapis.com/iid/v1/${token}/rel/topics/${topic}, {
   method: 'POST',
   headers: new Headers({
   'Authorization': key=YOUR_SERVER_KEY,
   }),
   }).then(response => {
   if (response.status < 200 || response.status >= 400) {
   throw Error subscribing to topic: ${response.status} - ${response.text()};
   }
   console.log(Subscribed to "${topic}");
   }).catch(error => {
   console.error('Error:', error);
   });
   }
   ```

1. Set up a listener to handle incoming messages when the app is in the foreground.

   ```javascript
   onMessage(messaging, (payload) => {
   console.log('Message received. ', payload);
   // Customize notification handling logic here
   });
   ```

1. Use the server key you got in Step 3 and the FCM endpoint to send topic messages.

   ```python
   import requests
   import json

   def send_fcm_topic_notification():
   server_key = 'YOUR_SERVER_KEY'
   topic = 'news' # Example topic
   headers = {
   'Content-Type': 'application/json',
   'Authorization': f'key={server_key}',
   }
   payload = {
   'to': f'/topics/{topic}',
   'notification': {
   'title': 'Breaking News',
   'body': 'Click to read the latest news!',
   },
   'data': {
   'key1': 'value1',
   'key2': 'value2',
   },
   }
   response = requests.post('https://fcm.googleapis.com/fcm/send', headers=headers, data=json.dumps(payload))
   print(response.status_code, response.text)
   send_fcm_topic_notification()
   ```

Each step needs to be followed in order to set up Firebase Cloud Messaging topic-based notifications correctly.