def add(data: dict[str, str], key_word: str, info: str) -> dict[str, str]:
    """Add provided key and value to the JSON file.

    Parameters
    ----------
    data : dict of str, str
        Internally used by `read` to pass in the current data
    key_word : str
        The key to be used
    info : str
        The value to be stored in the key

    Returns
    -------
    dict of str, str
        Internally used by the `write` decorator to update the current
        data.

    Raises
    ------
    Exception
        When the user doesn't want to override the value stored in the
        `keyword` when it already exists.
    """

    if key_word in data:
        message = (f'Are you sure you want to override {key_word} '
                   f'having value: {data[key_word]}?\t')
        if input(message) not in ('yes', 'y'):
            raise Exception('Exited')

    data[key_word] = info
    return data