PlayerScores.cs

using System.Collections;
using System.Collections.Generic;
using Proyecto26;
using UnityEngine;
using UnityEngine.UI;

public class PlayerScores : MonoBehaviour {
    public Text scoreText;
    public InputField nameText;

    private System.Random random = new System.Random ();

    User user = new User ();

    public static int playerScore;
    public static string playerName;

    // Start is called before the first frame update
    private void Start () {
        playerScore = random.Next (0, 101);
        scoreText.text = "Score: " + playerScore;
    }

    public void OnSubmit () {
        playerName = nameText.text;
        PostToDatabase ();
    }

    public void OnGetScore () {
        RetrieveFromDatabase ();
    }

    private void UpdateScore () {
        scoreText.text = "Score: " + user.userScore;
    }

    private void PostToDatabase () {
        User user = new User ();
        RestClient.Put ("https://stickman-pubg.firebaseio.com/" + playerName + ".json", user);
    }

    private void RetrieveFromDatabase () {
        RestClient.Get<User> ("https://stickman-pubg.firebaseio.com/" + nameText.text + ".json").Then (response => {
            user = response;
            UpdateScore ();
        });
    }
}