testing-library/react how to test invalid inputs when they dynamically generate error message

I am using Form in react. It has card number field. So if the user enters "333" and enters a tab, there is a dynamic message which shows up saying, "Card number needs to be a 16 digit number".

I am writing tests using @testing-library/react@9.5.0 and ts-jest@26.3.0.

Form Component:

CardForm.ts

users React-text-mask, Material UI to show an input which does validation by a schema which has a method to see if the input value is 16 or not and returns an error which is then displayed as helper text.

<form onSubmit={handleSubmit}>
<FormInput
  name="cardNumber"
  label="Card Number"
  inputMode="numeric"
  value={values.cardNumber}
  placeholder="XXXX-XXXX-XXXX-XXXX"
  validation={validationSchema.cardNumber}
  mask={formMasks.cardNumber}
/>
<Button
  type="submit"
  disabled={!values.card || validationSchema.cardNumber.errors.length === 0}
>
  CONFIRM CARD
</Button>
</form>

CardForm.test.tsx

import React from 'react';
import { render, fireEvent, screen } from '@testing-library/react';
import { CardForm } from '../components/Forms/CardForm';

const setup = () => {
    const utils = render(<CardEmailForm />);
    const input = utils.getByPlaceholderText('XXXX-XXXX-XXXX-XXXX');
    return {
        input,
        ...utils,
    };
};

test('show error message when card number entered is less than 16 digits', async () => {
    

    const { input, ...utils } = setup();

    fireEvent.change(input, {
        target: { value: '333' }, // I am giving the value 333 to the input
    });

    expect((input as HTMLInputElement).value).toBe('333 -    -    -    '); //works

    /* if I lose focus from the input, the error message shows up as helper text at the bottom of the input as shown above */
    fireEvent.blur(input); 
    
    /* now I am just expecting to read the error from the DOM based on h6 helper text, but this keeps giving me ERROR. */
    
    expect(await utils.getByRole('heading')).toHaveTextContent(
        'Card Number should be 16 numbers'
    );
});

ERROR!

 > 29 |     await screen.getByRole('heading');
         |               ^
      30 |  expect(screen.getByRole('heading')).toHaveTextContent(
      31 |      'Card Number should be 16 numbers'
      32 |  );

      at Object.getElementError (node_modules/@testing-library/dom/dist/config.js:34:12)
      at getMultipleElementsFoundError (node_modules/@testing-library/dom/dist/query-helpers.js:21:35)

Can someone help me write the expect statement so that once I give wrong input and then blur, I am able to read the error off the screen?