To download or update the Facebook app, follow these steps:

For Android devices:

• Open the Google Play Store app on your device.
• In the search bar, type “Facebook” and tap the search icon.
• Select the Facebook app from the search results.
• If you haven’t installed the app before, tap the “Install” button. If you already have the app installed and there’s an update available, you’ll see an “Update” button instead. Tap the “Update” button to download and install the latest version of the app.

For iOS devices:

• Open the App Store app on your device.
• In the search bar, type “Facebook” and tap the search icon.
• Select the Facebook app from the search results.
• If you haven’t installed the app before, tap the “Get” button. If you already have the app installed and there’s an update available, you’ll see an “Update” button instead. Tap the “Update” button to download and install the latest version of the app.

Once the app is installed or updated, you can log in using your Facebook account and start using the app.