[F] Fix return

src/utils.ts

@@ -73,7 +73,7 @@ export const Fmt = {
 export const Backend = {
   get: (id: string) => fetch(`${cfg.backend}/${id}`).then(r => {
     if (!r.ok) throw new Error(`Failed to get puzzle: ${r.status}`)
-    r.text()
+    return r.text()
   }).then(JsonTy.parse),
   post: (data: Checkpoint) => fetch(`${cfg.backend}/`, { method: "post", body: JsonTy.stringify(data) }),
 }