Best way to implement dynamic categories on a mobile game?

Hi, I'm doing a Worlde-like game with several word categories (ie: cities,countries,objects...) for Android, I was using TextAsset/Resources until now that I'm realising how stupid it is to build again and again everytime I want to add a new category to the game, instead I have been implementing Firebase to manage the categories given a .txt file with the categories inside, then I download the categories found in this file, but I'm getting errors in this last part, where Firebase claims that the asset can't be found on Firebase Storage, since It's my time with Firebase I think my code might be a mess and I'm not doing this the proper way... anyone knows what would be a good workaround for this? Any tip is appreciated :)

  void GetCategory(string item)
     {
         StorageReference text = reference.Child(item+".txt");
         Debug.Log(text.ToString());
         // Fetch the download URL
         text.GetDownloadUrlAsync().ContinueWithOnMainThread(tasks => {
             if (!tasks.IsFaulted && !tasks.IsCanceled)
             {
                 Debug.Log("Download URL: " + tasks.Result.ToString());
                 StartCoroutine(GetCategoryText(tasks.Result.ToString(),item));
             }
             else
             {
                 Debug.Log(tasks.Exception); **
             }
         });
     }
     IEnumerator GetCategoryText(string uri,string itemName)
     {
         UnityWebRequest www = UnityWebRequest.Get(uri);
         yield return www.SendWebRequest();
 
         if (www.isNetworkError || www.isHttpError)
         {
             Debug.Log(www.error);
         }
         else
         {
             // Show results as text
             TextAsset asset = new TextAsset(www.downloadHandler.text);
             asset.name = itemName;
             assets.Add(asset);
         }
     }

**Error is here: System.AggregateException: One or more errors occurred. ---> Firebase.Storage.StorageException: Object does not exist at location. --- End of inner exception stack trace --- ---> (Inner Exception #0) Firebase.Storage.StorageException: Object does not exist at location.<---