如何在react-final-form中注销字段？

import { Field } from 'react-final-form';

const MyForm = () => {
  return (
    <form>
      <Field name="username">
        {({ input }) => (
          <div>
            <label>Username</label>
            <input {...input} type="text" />
          </div>
        )}
      </Field>
      {/* 其他字段 */}
    </form>
  );
};

import { useForm } from 'react-final-form';

const MyForm = () => {
  const form = useForm();

  const handleButtonClick = () => {
    form.getFieldState('username').unregister();
  };

  return (
    <form>
      {/* 表单字段 */}
      <button type="button" onClick={handleButtonClick}>
        注销字段
      </button>
    </form>
  );
};