I am working on sending a reset token via email to a potential user in Node.js, Sequelize, and Express.The code works, but I still think it could be improved by handling the promises better.exports.sendResetToken = function(req,res) {  const username = req.headers.username;  User.findOne({    where: {username: username}  }).then((user) => {    if(user == null){      res.sendStatus(404);    } else {      let token = user.generateResetToken();      user.update({        resetToken: token,      }).then((user) => {        email.sendResetToken(user.email,user.resetToken);        res.sendStatus(200);      }).catch((err) => {        console.error(err);        res.sendStatus(400);      })    }    return null;  }).catch((err) => {    console.error(err);    res.sendStatus(401);  })}
Node.js Sequelize Promise
javascript;node.js;promise;express.js