If you know your backup phrase, you can delete the Freewallet Lite app and download it again. Further, import your mnemonic phrase in the newly downloaded app and create a new PIN code. If you haven’t written down your 12-word mnemonic phrase, the access to your funds is lost permanently.
Unfortunately, Freewallet Lite won’t be able to help you recover your funds as we don’t have any access to your backup phrase. This is why we always advise to backup your wallet.