import base64


def base64_to_hex(base64_string: str) -> str:
    """Convert base64 string to hexadecimal string

    Args:
        base64_string (str): Base64 string

    Returns:
        str: Hexadecimal representation
    """
    # Add padding to ensure valid padding
    return base64.b64decode(f"{base64_string}==").hex()