how to use describeSecret on firebase cloud function

I am upgrading my cloud functions on firebase from the first generation to the secondI use defineSecret to get a secret I have created on Google cloud, I need to deploy the functions, but the process doe not complete and givees me this error:

Error: Cannot access the value of secret “private_key” during function deployment. Secret values are only available at runtime.

this is the code of my function:

import * as admin from "firebase-admin";
import {defineSecret, defineString} from "firebase-functions/params";
const clientEmail = defineString("client-email");
const privateKey= defineSecret("private_key");
const projectId = defineString("project_key");
admin.initializeApp({
    credential: admin.credential.cert({
        privateKey: privateKey.value().replace(/\n/g, "n"),
        projectId: projectId.value(),
        clientEmail: clientEmail.value(),
    }),
    databaseURL: "myUrl",
});

const db = admin.firestore();
const realtime = admin.database();
export {admin, db, realtime};

what the error says is obvious, but I do not know what is wrong with my code; thanks in advance