Request payload отображается по другому

При клике на кнопку Log In на форме срабатывает событие onsubmit, описал это дело в функции, что не так делаю чтобы request payload отображался нормально? П.С. сайт написан на wordpress, axios использовать нельзя, все на ванильном js

<form id="loginForm" onsubmit="loginPreventDef(event)">
  <label for=""><input type="text" /></label>
  <label for=""><input type="password" /></label>
  <label for=""><input type="email" /></label>
  <button type="submit">Отправить</button>
</form>

<div class="section__block mb-3 pt-3">
  <form
    id="loginForm"
    name="loginForm"
    action="https://rankchecker.io/login"
    method="POST"
    onsubmit="loginPreventDef(event)"
  >
    <input
      name="_token"
      type="hidden"
      value="qDWW5od19yHRiXI0edWDpmWsCjbrFzsjHbDGTyNr"
    />
    <div class="form-group row">
      <div class="col-12 col-md-6 mx-auto">
        <input
          id="emailAddress"
          class="form-control"
          autocomplete="email"
          name="email"
          required=""
          type="email"
          value=""
          autofocus=""
          placeholder="Email"
        />
      </div>
    </div>
    <div class="form-group row">
      <div class="col-12 col-md-6 mx-auto">
        <input
          id="password"
          class="form-control"
          autocomplete="current-password"
          name="password"
          required=""
          type="password"
          placeholder="Password"
        />
      </div>
    </div>
    <div class="form-group row">
      <div class="col-12 col-md-6 mx-auto">
        <div
          class="g-recaptcha"
          data-sitekey="6LeJDsAUAAAAAHWKWE9FRlcp2ruwnEolOJsraeN1"
        >
          <div style="width: 304px; height: 78px">
            <div>
              <iframe
                title="reCAPTCHA"
                role="presentation"
                src="https://www.google.com/recaptcha/api2/anchor?ar=1&amp;k=6LeJDsAUAAAAAHWKWE9FRlcp2ruwnEolOJsraeN1&amp;co=aHR0cHM6Ly9yYW5rY2hlY2tlci5pbzo0NDM.&amp;hl=en&amp;v=f-bnnOuahiYKuei7dmAd3kgv&amp;size=normal&amp;cb=8bnklve4b76w"
                name="a-1glg4yumpzpq"
                scrolling="no"
                sandbox="allow-forms allow-popups allow-same-origin allow-scripts allow-top-navigation allow-modals allow-popups-to-escape-sandbox allow-storage-access-by-user-activation"
                width="304"
                height="78"
                frameborder="0"
              ></iframe>
            </div>
            <textarea
              id="g-recaptcha-response"
              class="g-recaptcha-response"
              style="
                width: 250px;
                height: 40px;
                border: 1px solid #c1c1c1;
                margin: 10px 25px;
                padding: 0px;
                resize: none;
                display: none;
              "
              name="g-recaptcha-response"
            ></textarea>
          </div>
          <iframe style="display: none"></iframe>
        </div>
      </div>
    </div>
    <div class="form-group row mb-0">
      <div class="col-md-8 mx-auto text-center">
        <button class="btn btn-lg btn-success px-5" type="submit">
          Log In
        </button>
      </div>
      <div class="col-md-8 mx-auto text-center">
        <a class="btn btn-link font-weight-bold" href="/password-reset">
          Forgot Your Password?
        </a>
      </div>
    </div>
  </form>
</div>

function loginPreventDef(e) {
  e.preventDefault()

  const formData = new FormData(document.getElementById('loginForm'))

  fetch('/login', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: formData,
  })
    .then((response) => {
      if (response.ok) {
        return response.json()
      }
      return Promise.reject(response)
    })
    .then((data) => console.log(data))
    .catch((error) => console.error(error))
}