how to display image in custom post type from frontend form using advanced custom field?

here is my code:
employeedetails.php

<div class="container submit-message">
    <h1>Employee Form</h1>
    <form id="enquiry_email_form" action="#" method="POST" data-url="<?php echo admin_url('admin-ajax.php'); ?>" enctype="multipart/form-data">
    <div class="form-group">
            <label for="">Enter Title</label>
            <input type="text" class="form-control" name="title" id="title"/>
        </div>
        <div class="form-group">
            <label for="">Enter Description</label>
            <input type="text" class="form-control" name="description" id="description"/>
        </div>
        <div class="form-group">
            <label for="">Enter Your Name</label>
            <input type="text" class="form-control" name="post_name" id="post_name"/>
        </div>
        <div class="form-group">
            <label for="">Enter Your Designation</label>
            <input type="text" name="post_designation" id="post_designation" class="form-control"/>
        </div>
        <div class="form-group">
            <label for="">Salary</label>
            <input type="text" class="form-control" name="post_salary" id="post_salary"/>
        </div>
        <div class="form-group">
            <label for="">Enter Joining Date</label>
            <input type="date" class="form-control" name="post_date" value="<?php echo date('Y-m-d'); ?>" id="post_date"/>
        </div>   
        <div class="form-group">
            <label for="">Select Image</label>
            <input type="file" id="post_img" name="post_img" src="https://wordpress.stackexchange.com/<?php bloginfo("template_url'); ?>" value="" accept="image/*""/>
        </div>
        <div class="form-group">
            <button type="submit" class="btn btn-primary"><i class="glyphicon glyphicon-pencil"></i> Submit</button>
        </div>
    </form>
</div>

$(document).ready(function() {
$(“#enquiry_email_form”).on(“submit”,function(event){
event.preventDefault();

/* Clear result div
$(“#data”).html(”);
*/

var form= $(this);
var ajaxurl = form.data(“”);

// var image = $(‘#post_img’).prop(‘files’)(0);
var post_title = form.find(“#title”).val();
var post_description = form.find(“#description”).val();
var post_name = form.find(“#post_name”).val();
var post_designation = form.find(“#post_designation”).val();
var post_salary = form.find(“#post_salary”).val();
var post_date = form.find(“#post_date”).val();
var post_img = form.find(“#post_img”).val();

/*console.log(post_title);
console.log(post_description);
console.log(post_name);
console.log(post_designation);
console.log(post_salary);
console.log(post_date);
console.log(post_img);*/
/*if(detail_info.post_title === “” || detail_info.post_description === “” || detail_info.post_designation === “” || detail_info.post_salary === “”
|| detail_info.post_date === “” || detail_info.post_img === “”) {
alert(“Fields cannot be blank”);
return;
}*/
$(“.btn btn-primary”).text(‘submitting…’);
$.ajax({
url: “/wp-admin/admin-ajax.php”,
type: ‘POST’,
data: {
action: ‘save_post_details_form_employee’, // this is going to be used inside wordpress functions.php
post_title : post_title,
post_description : post_description,
post_name : post_name,
post_designation : post_designation,
post_salary : post_salary,
post_date : post_date,
post_img : post_img
},
success: function(data) {
//alert(“Insert Success”);
//console.log(data);
// Show successfully for submit message
$(“.submit-message”).html(‘Thank you for submitting’);
}
});
});
});