Sharing from iPhone to ipad

Assuming that both your iPhone and iPad are signed-in to iCloud with the same Apple Account (formerly known as your AppleID) - and that you have enabled Passwords & Keychain synchronisation - all of your saved sign-in credentials will be synchronised and available to both devices. On both devices:

Settings > [Your Name / Apple Account] > iCloud > [Saved to iCloud] > Passwords - sync this iPhone|iPad

Passwords should auto-fill if your device settings are configured to do so:

Settings > General > Autofill Passwords >

• AutoFill Passwords and Passkeys - set to ON
• [Autofill from] Passwords - set to ON

Your saved Passwords and account credentials can also be accessed manually from the Passwords App.

The iPad User Guide provides much more information. Here are two direct links to relevant sections of the Guide:

Automatically fill in strong passwords on iPad - Apple Support

Use passwords on iPad - Apple Support

if it was me then I would go to the iphone and open the password app

scroll down to f and click facebook and click the password field, which will then display the password