Submit Laravel form after Authentication

i have a modal form with tabs, i use ajax in submitting the form which work fine. I want the form should be public, if the user is not login it should display login and submit the form after logging in using ajax and laravel.

public function acServices()
{
$id = Auth::user()->id;
$post = new Ac_services_request  ;
$post->user_id = $id;
$post->services = Request::input('service');
$post->ac_type = Request::input('ac_type');
$post->type_services = Request::input('ac_services');
$post->no_of_ac = Request::input('no_of_ac');
$post->other_info = Request::input('other_info');
$post->address = Request::input('addr');
$post->landmark = Request::input('landmark');
$post->lga = Request::input('lga');
$post->specific_location = Request::input('specific_location');
$post->date = Request::input('date');
$post->time = Request::input('time');
$post->mobile = Request::input('');
$post->code = $string."".$id;

$post->save();
return 'success';
}



<div class="modal fade ac-services ativa-scroll" data-backdrop="static"  
  data-keyboard="false" id="ac-services" tabindex="-1" role="dialog">
 <div class="modal-dialog "  role="document">
    <div class="modal-content " >
     <button  type="button" class="close" data-dismiss="modal" aria-
 label="Close">
  <span style="color: white;" aria-hidden="true">&times;</span>
</button>

  <form class="contact" >
  <div class="setup-content" id="step-1">

  <div class="form-group input-group col-md-9">
  <p>Select AC type</p>
   <select required="required" class="form-control lg" name="ac_type">

      <option></option>
       <option>Window AC(S)</option>
       <option>Split AC(S)</option>
        <option>Window AC(S) and Split AC(S)</option>
       </select>
     </div>
  <input type="hidden" name="service" value="A/C Repairs and Services">
  <div class="form-group input-group col-md-9">
   <p>Select type of service you need</p>
 <select required="required" class="form-control lg" name="ac_services">
    <option></option>
       <option>Installation of new AC</option>
       <option>General Cleaning</option>
       <option>Un-installation of existing AC</option>
       <option>Repairs (Diagnosis and rectification of AC(s)</option>
       </select>

     </div>   
    <button class="btn btn-primary nextBtn btn-lg pull-right" 
    type="button">Next</button>
      </div>
    <div class="row setup-content" id="step-2">

    <div class="form-group input-group col-md-9">
         <p>How many AC(s)</p>

     <input  type="number" required="required" class="form-control lg" 
  name="no_of_ac" placeholder="Enter Number of AC e.g 2" >
             </div>
    <div class="form-group ">
       <p>Other Informations</p>
     <textarea required="required" rows="5" cols="65" name="other_info">
  </textarea>
  </div>
 <button class="btn btn-primary prevBtn btn-lg pull-left" 
  type="button">Back</button>
  <button class="btn btn-primary nextBtn btn-lg pull-right" 
  type="button">Next</button>

  </div>
  <div class="row setup-content" id="step-3">

  <div class="form-group input-group col-md-9">
  <p>Where do you need the services ?</p>

      <span>House/Flat No, Street, City</span>
     <input type="text" required="required" class="form-control lg" 
    name="addr">
 </div>

     <div class="form-group input-group col-md-9">
   <span>Landmark</span>
   <input type="text" required="required" class="form-control lg" 
    name="landmark">
     </div>

      <div class="form-group input-group col-md-9">
   <span>LGA</span>
   <input type="text" required="required" class="form-control lg" 
   name="lga" >
   </div>
       <div class="form-group input-group col-md-9">
      <span>Any other specific location direction/description?</span>
     <input type="text" required="required" class="form-control lg" 
     name="specific_location"><br>
     <span><b> Note: Accurate location helps us reach you promptly </b> 
    </span>
    </div>


   <button class="btn btn-primary prevBtn btn-lg pull-left" 
   type="button">Back</button>
   <button class="btn btn-primary nextBtn btn-lg pull-right" 
   type="button">Next</button>
      </div>

      <div class="row setup-content" id="step-4">

      <div class="form-group input-group col-md-9">
      <p>Pick Date</p>
      <input type="date" required="required" class="form-control lg" 
      name="date">                  </div>
      <div class="form-group ">
      <p>Select Service Time</p>
              <select required="required" class="form-control lg" name="time">
              <option></option>
                <option>10:00am - 11:00am</option>
                <option>11:00am - 12:00pm</option>
                   <option>12:00pm - 1:00pm</option>
                    <option>1:00pm - 2:00pm</option>
                     <option>2:00pm -3:00pm</option>
                      <option>3:00pm - 4:00pm</option>
                       <option>4:00pm - 5:00pm</option>
              </select> 
       </div>
       <button class="btn btn-primary prevBtn btn-lg pull-left" type="button">Back</button>
      <button class="btn btn-primary prevBtn btn-lg pull-right" id="submit" data-
      target=".success">submit</button>
     </div>

    <script>
    $('#ac-services').on('hidden.bs.modal', function () {
    location.reload();
    })
    $(function() {
    $("button#submit").click(function(){

    $.ajax({
    url: 'ac-booked-service',
    type: "post",
    data: $('form.contact').serialize(),
    beforeSend: function() {                    
   $empty = $('form.contact').find("input").filter(function() {
   return this.value === "";
   });
   if($empty.length) {
   alert('Please fill all the field');
  return false;
  }else{
  return true;
  };
  },

  success: function (result) {
  window.location.replace('/user/dashboard');  

     },
    error: function(){
   alert("failure");
   }  
   });
   });
   });
 </script>