How to parse MongoDB int32 in node.js
Note the db.collection(&quot;players&quot;).find(query).toArray() returns an array of documents - these are available as result array. Your code console.log(result.balance) returned undefined - as you are looking for a property called balance in the array. You could do that on an object (or document) which has a property with that name - not on the array.
Retrieve an individual property from an array of objects - do the following to print each document's balance property value:
result.forEach(doc =&gt; console.log(doc.balance));

Here is your function's code in a slightly different way:
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017';

MongoClient.connect(url, { useUnifiedTopology: true }, function(err, client) {
    if (err) throw err;
    console.log(&quot;Connected successfully to server&quot;);
    const db = client.db(&quot;DiscordDB&quot;);
    const id = &quot;some value&quot;; // input value
  
    findBalance(db, id, function(result) {
        console.log(JSON.stringify(result));
        result.forEach(doc =&gt; console.log(doc.balance));
        console.log(&quot;Closing connection.&quot;);
        client.close();
    });
});

const findBalance = function(db, id, callback) {
    const query = { uuid: id };
    db.collection(&quot;players&quot;)
        .find(query)
        .toArray(function(err, result) { 
            if (err) throw err; 
            console.log(&quot;Query ran okay&quot;);
        callback(result); 
    }); 
};