“FB password finder: paste a profile link or Facebook ID and get the password.”
A profile link or a user ID is not a key. Facebook lists the user ID among the profile details that are always public, so the page is asking for something anyone can already see. On the other side, Meta wrote in 2019 that a password is masked the moment the account is created — hashed with a salt, with the scrypt function named — and a login is checked against that result, not against readable text. A finder would need a readable copy, and there is none to look up. The same post owned up to an internal slip: some passwords had ended up readable in internal logs, with no abuse and no outside access found, according to Meta. That was a fault inside Meta's systems, not something a public page can query.