PAVLOVIA - unable to translate code component (Python) into Pavlovia (Java) to run experiment online

URL of experiment:

Version of Psychopy3: PsychoPy 2020.2.8

Description of the problem:
Dear all,

I have a problem with a code component that includes visual.ButtonStim variable, it works perfectly in PsychoPy but does not work on Pavlovia because the Java script does not decode it.

Here is my code in Code Component:
Begin routine (Py):
continueButton = visual.ButtonStim(win, labelText = “POKRAČOVAT”,
pos = (0, -0.4))

Begin routine (Java):
ButtonStim(psychoJS.window, {“labelText”: “POKRA\u010cOVAT”, “pos”: [0, (- 0.4)]});

Each frame (Py):
continueButton.buttonEnabled = True

if continueButton.buttonSelected:
continueRoutine = False

Each frame (Java):
continueButton.buttonEnabled = true;
if (continueButton.buttonSelected) {
continueRoutine = false;

When I run it on Pavlovia, I get the following error message:
visual.ButtonStim is not a constructor

I know that several colleagues here might have tried to sort out a similar problem, nevertheless, I would be grateful for your advice / recommendation/ reply as I am completely new to Python and Java.

Many thanks in advance.

All the best,