AndroidJavaObject not implemented in app unity

public AndroidRecognitionBridge()
        {
            Debug.Log("Initializing bridge...");
            _recognizeBridge = new AndroidJavaObject("com.mirai.recogbridge.BridgeUnity");
            string dirPath = _recognizeBridge.Call<string>("GetExternalPath");

            _recognizeBridge.Call("Init", dirPath + "/data_train/");

            _recognizeBridge.Call("SetKanji");
            _recognizeBridge.Call("SetOneLinePunctuation", true);
            _pointList = new List<Point>();
        }

so, i tried to build my project with this code with unity 2019.4.39, but when i extract the apk file, the "data_train" file is not inserted in apk so how do i implement the data_train file?

thank you