FirebaseDatabase.cs

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public static class FirebaseDatabase
{

    public static IEnumerator Send<T>(string firebaseUrl, T content)
    {

        return Send(firebaseUrl, JsonUtility.ToJson(content));

    }

    public static IEnumerator Send(string firebaseUrl, string jsonData)
    {

        using (UnityWebRequest request = UnityWebRequest.Put(firebaseUrl, jsonData))
        {

            request.method = "PATCH";

            Debug.LogFormat("firebaseUrl: {0}", firebaseUrl);
            Debug.LogFormat("jsonData: {0}", jsonData);

            yield return request.SendWebRequest();

            if (request.isNetworkError || request.isHttpError)
            {

                Debug.LogError(request.error);

            }

        }

    }

}