Username doesn't get updated after running this. I also tried UpdateOne and it didn't work as well. The code was supposed to update an array but I tried updating the username to make it easier to track down the problem.

const mongoose = require('mongoose');

const schema = mongoose.Schema;

const userSchema = new schema({
    Username:{
        type: String,
        required: true
    },
    Password:{
        type: String,
        required: true
    },
    Cart: Array
});

const User = mongoose.model('User', userSchema);
module.exports = User;

.

app.post('/putbox', (req, res) => {


    var query = { Username: user };

    var newvalues = { $push: { Cart: "Boxing" } };

    try{

        User.find(query).then((d)=>{

            var values = d[0].Cart;
            values.push("boxing")

            User.findByIdAndUpdate(d._id, {Username: "test1"})

        });

    } catch(err) {
        console.log(err);
    } 

    res.redirect('/boxing');

});