Empty response for JWT login Node.js

I'm trying to make a simple authentication system on my Node.js API. Actually, I had the login endpoint working like a charm with JWT, but I also wanted to implement a logout function (and not have to wait for the token to expire) so I looked up how to achieve it.

After doing an exhaustive research on how to do it from the server side, I decided to install the jwt-redis package, which is suposed to not only repeat the entire functionallity of jsonwebtoken, but also store tokens in Redis and be able to destroy them with a simple method.

The fact is that now, after following the instructions on its readme, and although the endpoint is returning a successful status when testing with Postman, the response body (where the access token should be) is empty.

I attach my code below.

async login(req, res) {
    try {
        const redis = require('redis');
        const JWTR =  require('jwt-redis').default;
        //ES6 import JWTR from 'jwt-redis';
        const redisClient = redis.createClient();
        const jwtr = new JWTR(redisClient);
        redisClient.on("error", function (err) {
            console.log("Error " + err)
        })
        await redisClient.connect()

        console.log('email:' + req.body.email)
        console.log('hola')
        let user = await this.adapter.getByLogin(req.body.email)
        if (!user) return res.status(404).json({ Error: 'Recurso no encontrado' })

        const bcrypt = require('bcrypt')
        console.log(req.body.password, user.password)
        bcrypt.compare(req.body.password, user.password, (error, result) => {
            console.log(error, result)

            if (error) return res.status(404).json({ Error: 'Recurso no encontrado' })
            if (!result) return res.status(404).json({ Error: 'Recurso no encontrado' })

            delete user.password

            var payload = { jti: req.body.email }

            const accessToken = jwtr.sign(payload, process.env.ACCESS_TOKEN_SECRET)
            //console.log('accessToken:' + JSON.stringify(accessToken))
            res.json(accessToken)
        })
    } catch (error) {
        return res.status(500).json({ error: 'Recurso no encontrado', stacktrace: error })
    }
}

Please, take in care that I'm pretty new in JavaScript and Back-end development, so probably it is due to a dummie mistake. Anyway, I will appreciate your help, either if you have worked with this library before and you know where the error is, or you have any other idea of how I can make both login and logout work properly using JSON web token.

Thanks in advance.