How to work with Rust?

[AuroraLantean]

Why does my Rust-Analyzer not work after installing this extionsion???
Why does my Rust code below got highlighted by the default setting of
"todohighlight.keywordsPattern": "TODO:|FIXME:|\\(([^)]+)\\)", //highlightTODO:,FIXME:` or content between parentheses`` ?

pub async fn get_all_todos(State(db): State<MySqlPool>) -> impl IntoResponse {
        let res: Result<Vec<Self>, sqlx::Error> = sqlx::query_as(
            "SELECT id, title, description, status
            from todos
          ",
        )
        .fetch_all(&db)