Fix all compilation issues.

backend/exposition/src/lib.rs

@@ -4,6 +4,7 @@ use crate::user::validator::validator;
 use actix_web::web::ServiceConfig;
 use actix_web::{get, web, HttpResponse, Responder};
 use actix_web_httpauth::middleware::HttpAuthentication;
+use crate::video::handler::download_file;
 
 pub mod user;
 pub mod video;
@@ -14,6 +15,7 @@ async fn health() -> impl Responder {
 }
 
 pub fn init(cfg: &mut ServiceConfig) {
+    cfg.service(download_file);
     cfg.default_service(web::to(not_found));
 }