Как исправить ошибку "event.target.reset is not a function"

const validation = new JustValidate('#form', {
  errorFieldCssClass: 'is-invalid',
  errorFieldStyle: {
    border: '5px solid red',
  },
  errorLabelStyle: {
    fontSize: '12px',
    color: '#fcee09',
    margin: '7px 0 0',
    display: 'flex',
    alignItems: 'center',
    justifyContent: 'flex-end'
  },
  errorLabelCssClass: 'error',
  successFieldCssClass: 'is-valid',
  focusInvalidField: true,
  lockForm: true,
  // errorsContainer: '.errors-container',
}, [{
    key: 'Field is required',
    dict: {
      ru: 'Поле, обязательное для заполнения',
    },
  },
  {
    key: 'Name is too short',
    dict: {
      ru: 'Имя слишком короткое',
    },
  },
  {
    key: 'Name is too long',
    dict: {
      ru: 'Имя слишком длинное',
    },
  },
  {
    key: 'Email is required',
    dict: {
      ru: 'Email - обязательное поле',
    },
  },
  {
    key: 'Email is invalid',
    dict: {
      ru: 'Указан некорректный Email',
    },
  },
  {
    key: 'Phone is invalid',
    dict: {
      ru: 'Указан некорректный телефон',
    },
  },
  {
    key: 'Message is too short',
    dict: {
      ru: 'Сообщение слишком короткое',
    },
  },
  {
    key: 'Message is too long',
    dict: {
      ru: 'Сообщение слишком длинное',
    },
  }
]);


validation.setCurrentLocale('ru');
validation
  .addField('#name', [{
      rule: 'required',
      errorMessage: 'Field is required',
    },
    {
      rule: 'minLength',
      value: 3,
      errorMessage: 'Name is too short',
    },
    {
      rule: 'maxLength',
      value: 30,
      errorMessage: 'Name is too long',
    },
  ])
  .addField('#email', [{
      rule: 'required',
      errorMessage: 'Email is required',
    },
    {
      rule: 'email',
      errorMessage: 'Email is invalid',
    },
  ])
  .addField('#tel', [{
      rule: 'required',
      value: true,
      errorMessage: 'Field is required',
    },
    // {
    //  rule: 'function',
    //  validator: async function () {
    //      const phone = tel.inputmask.unmaskedvalue();
    //      return phone.length === 1;
    //  },
    //  errorMessage: 'Phone is invalid',
    // },
    {
      rule: 'minLength',
      value: 16,
      errorMessage: 'Phone is invalid',
    },
    // {
    //  rule: 'maxLength',
    //  value: 16,
    //  errorMessage: 'Phone is invalid',
    // },
  ])
  .addField('#message', [{
      rule: 'required',
      errorMessage: 'Field is required',
    },
    // {
    //  validator: (value) => {
    //      return value[1] === '!';
    //  },
    // },
    {
      rule: 'minLength',
      value: 30,
      errorMessage: 'Message is too short',
    },
    {
      rule: 'maxLength',
      value: 150,
      errorMessage: 'Message is too long',
    },
  ]).onSuccess((event) => {
    console.log('Validation passes and form submitted', event.target, event.target.reset);

    let formData = new FormData(event.target);

    console.log(...formData);

    let xhr = new XMLHttpRequest();

    xhr.onreadystatechange = function() {
      if (xhr.readyState === 4) {
        if (xhr.status === 200) {
          console.log('Отправлено');
        }
      }
    }

    xhr.open('POST', 'mail.php', true);
    xhr.send(formData);

    event.target.reset();
  });


document.getElementById('reset').addEventListener('click', function() {
  validation.refresh();
})

<script src="https://unpkg.com/just-validate@latest/dist/just-validate.production.min.js"></script>
<form class="contact__form form" id="form" action="#" method="POST" enctype="multipart/form-data" autocomplete="off">
  <div class="form__item">
    <input class="form__input form__input_name" id="name" type="text" name="name" required="">
    <label class="form__label form__label_one" for="name"></label>
  </div>
  <span class="cyberpunk glitched"></span>
  <div class="form__item">
    <input class="form__input form__input_email" id="email" type="email" name="email" required="">
    <label class="form__label form__label_two" for="email"></label>
  </div>
  <span class="form__hr"></span>
  <div class="form__item">
    <input class="form__input form__input_tel" id="tel" type="tel" name="tel" required="">
    <label class="form__label form__label_three" for="tel"></label>
  </div>
  <span class="form__hr"></span>
  <div class="form__item form__item_textarea">
    <textarea class="form__textarea form__textarea_message" id="message" name="message" required=""></textarea>
    <label class="form__label form__label_four" for="message"></label>

  </div>
  <div class="form__buttons">
    <button class="form__button form__button_reset" id="resetB" type="reset">
        <span class="form__button-text">сброс_</span>
        <span class="form__button-glitch">сброс_</span>
        <span class="form__button-tag">R19</span></button>
    <button class="form__button form__button_send" type="submit">
        <span class="form__button-text">отправить_</span>
        <span class="form__button-glitch">отправить_</span>
        <span class="form__button-tag">R05</span></button>
  </div>
</form>