To save your password on the Facebook app, you can use your phone's built-in password manager or a third-party password manager app. Here's how you can do so:

Step 1. Open the Settings app on your Android or iOS smartphone.

Step 2. Scroll down and tap on Google (for Android) or Passwords (for iOS).

Step 3. Turn on the Autofill or Autofill Passwords toggle.

Step 4. Return to the Facebook app and log in.

Step 5. Finally, select Save or Save Password to store your password on your device.

Note: Storing passwords can help you manage your login credentials for various apps. However, ensure you use a strong and unique password to keep your data secure.

Changing your Facebook password can help you keep your account protected. Follow the steps below to change your Facebook password on Android:

Step 1. Open the Facebook app and click on the menu icon.

Step 2. Tap Settings & Privacy and click the Security & Login section.

Step 3. Click on the Change Password button in the Login tab and change your password.

Note: You'll be logged out of all devices after you change the password. So, you'll need to log in again on your other devices.

If you see any suspicious activity and want to check your Facebook login history on your phone, follow the steps below:

Step 1. Open the Facebook app on your phone and tap on the menu icon.

Step 2. Scroll down and tap on the Settings & Privacy section.

Step 3. Now, scroll down to the Security section and tap on the Security and Login tab.

Step 4. Look for the Where You're Logged In section, and you'll see a list of devices your account has been accessed from recently.

Here, you can check the login history, such as the date, time, device type, and location.

Note: Always use a strong, unique password for your Facebook account and enable 2FA or two-factor authentication for added security.