expected opaque type, found enum `Result`

Question

when I want to match the result of a function in rust like this:

#[get("/v1/user")]
pub fn user_info(){
    match get_user_info(16){
        Ok(sk) => {
            info!("get user info success:" + sk)
        },
        Err(e) => {
            info!("error:" + e)
        },
    }
}

shows error like this:

error[E0308]: mismatched types
  --> src/biz/music/test_controller.rs:53:9
   |
53 |         Ok(sk) => {
   |         ^^^^^^ expected opaque type, found enum `Result`
   |
note: while checking the return type of the `async fn`
  --> src/common/net/rest_client.rs:4:50
   |
4  | pub async fn get_user_info(input_user_id:i64) -> Result<(), Box<dyn std::error::Error>> {
   |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ checked the `Output` of this `async fn`, expected opaque type
   = note: expected opaque type `impl std::future::Future`
                     found enum `Result<_, _>`

error[E0308]: mismatched types
  --> src/biz/music/test_controller.rs:57:9
   |
57 |         Err(e) => {
   |         ^^^^^^ expected opaque type, found enum `Result`
   |
note: while checking the return type of the `async fn`
  --> src/common/net/rest_client.rs:4:50

and this is my get_user_info function:

pub async fn get_user_info(input_user_id:i64) -> Result<(), Box<dyn std::error::Error>> {
    let url = "http://dolphin-post-service.reddwarf-pro.svc.cluster.local:11014/post/user/";
    let uid = string_to_static_str(input_user_id.to_string());
    let resp = reqwest::get(format!("{}{}", url, uid))
        .await?
        .json::<HashMap<String, String>>()
        .await?;
    println!("{:#?}", resp);
    Ok(())
}

how to solve this problem, I am search from internet and tell me that the function is return a Future, but I did not found a await keyword in rust, how to handle this situation? what should I do to make it work?