The method applyTheme dosen`t exist in surveyjs. How to change theme or css in a survey react nodejs

I’m trying to change the apperance of a survey in surveyjs forms library. According to document I have to use survey.applyTheme() but there are no such thing. I’ve imported the defaultV2.min.css

Please help me change the colors or set up a css or theme in surveyjs, react, nodejs. I hope this is enough information!

This is what i’ve done but the applyTheme is not there?!:

import { Model } from "survey-core";
 /*
   Don't forget to import or reference the         Default V2 style sheet
   as described in the Get Started with     SurveyJS article for your framework
 */
 import { LayeredDarkPanelless } "survey-core/themes/layered-dark-panelless";

const surveyJson = { ... };
const survey = new Model(surveyJson);
survey.applyTheme(LayeredDarkPanelless);```

I solved it this way:

import * as Survey from "survey-react-ui";
import { ComponentCollection } from "survey-core";
import { Model } from "survey-core";
import * as SurveyTheme from "survey-core/themes";
import "survey-core/defaultV2.min.css";

const [survey, setSurvey] = useState(null);

  useEffect(() => {
    const newSurvey = new Model(surveyJSON);
    newSurvey.applyTheme(SurveyTheme.DefaultDark);
    setSurvey(newSurvey);
    return () => {};
  }, [surveyJSON]);

 return (
    <>
      {surveyJSON && (
        <Survey.Survey
          model={survey}
          onComplete={handleOnComplete}
          onAfterRenderQuestion={handleAfterRenderQuestion}
          onCurrentPageChanged={handlePageChange}
        />
      )}
    </>
  );