Bunu denebilirsin.

    app.use((req, res, next) => {
    const allowedOrigins = ['http://localhost:5174', 'http://localhost:5173'];
    const origin = req.headers.origin;
    if (allowedOrigins.includes(origin)) {
        res.setHeader('Access-Control-Allow-Origin', origin);
    }
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
    next();
});