pls work

backend/src/main/resources/get/cesare.js

@@ -23,7 +23,8 @@ async function decrypt() {
             method: "POST", headers: { "Content-Type": "application/json" },
             body: JSON.stringify({ ciphertext: ciphertext })
         });
-        document.getElementById("decodedtext").value = await res.JSON;
+        const data = await res.json();
+        document.getElementById("decodedtext").value = JSON.stringify(data, null, 2);
     } catch (e) { alert("Errore di connessione!"); }
 }