Error Validation after firing

Question

I have the following function that fires a form

I would like in case that mistake showed showValidationError on sweetalert2.

At least to say that the field is mandatory or error when saving

$('.btn-ok').on('click', function(){
forumalario()
})


async function forumalario(){

  const {value: formValues} = await Swal.fire({
    title: 'Multiple inputs',
    html:
      '<input id="swal-input1" class="swal2-input">' +
      '<input id="swal-input2" class="swal2-input">',
    focusConfirm: false,
    preConfirm: () => {
      return [
        document.getElementById('swal-input1').value,
        document.getElementById('swal-input2').value
      ]
    }
  })

  if (formValues) {
    console.log('campos', JSON.stringify(formValues))
    Swal.fire(json.stringify(formValues))
    
  }
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>
<link href="https://cdnjs.cloudflare.com/ajax/libs/limonte-sweetalert2/7.33.1/sweetalert2.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/limonte-sweetalert2/7.33.1/sweetalert2.all.js"></script>

<script
  src="https://code.jquery.com/jquery-3.3.1.min.js"
  integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
  crossorigin="anonymous"></script>
  
  <a href="#" class="btn btn-xs btn-ok">OK</a>

Just like this email example they have

$('.btn-click').on('click', function(){
  click()
})

async function click(){
    const {value: email} = await Swal.fire({
    title: 'Input email address',
    input: 'email',
    inputPlaceholder: 'Enter your email address'
  })

  if (email) {
    Swal.fire('Entered email: ' + email)
  }
}

 <link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/limonte-sweetalert2/7.33.1/sweetalert2.css" rel="stylesheet"/>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/limonte-sweetalert2/7.33.1/sweetalert2.all.js"></script>

    <script
      src="https://code.jquery.com/jquery-3.3.1.min.js"
      integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
      crossorigin="anonymous"></script>
      
      
     <a href="#" class="btn btn-click">click</a> 

I would like to implement this error validation