Function send_request 

pub async fn send_request<T: DeserializeOwned>(
    access_key: &str,
    secret_key: &str,
    endpoint: &str,
    region: &str,
    service: &str,
    method: &str,
    content_type: &str,
    query_params: BTreeMap<&str, &str>,
    body_params: Value,
) -> Result<T, Box<dyn Error>>