Viewing object returned from realm.object()

I added data to a realm using

realm.write(() => {
    for (const player in players) {
      realm.create('Player', {
        firstname: player.firstname,
        lastname: player.lastname,   

players is a JSON array.

    "id": 9687,
    "firstname": "Nyeem",
    "lastname": "Young",
    "id": 100,
    "firstname": "Jason",
    "lastname": "Holder",

I was able to confirm that the data was entered successfully by using

realmPlayers = realm.objects('Player');
console.log(`There are ${realmPlayers.length} players`); // 99

However when I try to get all the players


I get the error

[TypeError: item.toJSON is not a f
unction. (In 'item.toJSON(index.toString(), cache)', 'item.toJSON' is undefined)]

console.log(JSON.stringify(realmPlayers)); gives the same error.
console.log(realmPlayers[0]); returns {}

Trying to use a filter

realm.objects('Player').filtered('lastname = Young');

I get the error

Failed to open the realm 'Player' has no property: 'Young'

If I have items in the database why can’t I access it. Ultimately what I want to do is to get all the items in the database and pass the result to a FlatList component in React Native…

How can the data and possible visualize it via the command line?