Return the authorization token
        :return: string

def get_auth_token(cls):
        """
        Return the authorization token
        :return: string
        """
        if 'Authorization' not in f_request.headers:
            raise ValueError("Missing Authorization Bearer in headers")
        data = f_request.headers['Authorization'].encode('ascii', 'ignore')
        return str.replace(str(data), 'Bearer ', '').strip()