Cannot read properties of undefined (reading '0') using React Testing library

Question

I'm trying to get the instance of my app here, and I can't find a way to get it with findInstance... here is my test

 it('should call dispatchMWIUpdateError', () => {
  const cmp = render(<App {...props} />);
  findInstance(cmp).dispatchAction('testField', 'testValue', 'header', true);
  expect(findInstance(cmp).props.appActions.dispatchMWIUpdateError).toHaveBeenCalled();
  expect(props.appActions.dispatchMWIUpdateError).toHaveBeenCalled();
});

resource: testing-with-react-testing-library-using-component-instances

is there a way to get the instance of my app to test method name dispatchAction()?