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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def decrypt(crypt_text) -> str:
 """ Use config.json key to decrypt """

        cipher = Fernet(current_app.config['KEY'])
        if not isinstance(crypt_text, bytes):
            crypt_text = str.encode(crypt_text)
        return cipher.decrypt(crypt_text).decode("utf-8")