don’t understanding why my cookie doesn’t appear

i can’t see my cookie with the dev tool and don’t understand if its because my cookie is poorly set up or it is because it is set up but at a place I can’t see
i try using the mehtode of res.setHeader but I didnt work either so I run out of option know fore me

const express = require("express");
const cookieParser = require("cookie-parser");
const path = require("path");
const { createClient } = require("@supabase/supabase-js");
const { createServer } = require("node:http");
const { join } = require("node:path");
const { Server } = require("socket.io");
var cors = require("cors");
const { error } = require("console");

const app = express();
const server = createServer(app);
const io = new Server(server);

const supabaseUrl = "myurl";
const supabaseKey = "mykey";
const supabase = createClient(supabaseUrl, supabaseKey);

const port = process.env.PORT || 5000;
const corsOptions = {
    origin: "http://localhost:3000",
    optionsSuccessStatus: 200,
};

app.use(cookieParser());
app.use(cors(corsOptions));
app.use(express.json());

async function authenticate(userIdFromCookie) {
    console.log("appelle de la fonciton authenticate");
    if (userIdFromCookie !== undefined) {
        console.log("User ID found in cookie:", userIdFromCookie);
        return true;
    } else {
        return false;
    }
}

app.post("/chat", async function (req, res) {
    try {
        const userId = req.body.userId;
        const isAuthenticated = await authenticate(userId);
        if (!isAuthenticated) {
            const { data, error } = await supabase.from("post").select();
            if (error) {
                return res.status(500).json({
                    error: `Error fetching data from Supabase`,
                });
            }
            res.cookie("userId", 3);
            console.log("cookie setup");
            return res.json(data);
        } else {
            return res
                .status(500)
                .json({ error: "activer les cookies ou recharger la page svp" });
        }
    } catch (err) {
        console.error(err);
        res.status(500).json({ error: "Internal Server Error" });
    }
});