$('.import-btn').on('click', function() {
            $.ajax({
                url: '<?php echo admin_url('admin-ajax.php'); ?>',
                type: "POST",
                data: {
                    action: 'import_data'
                },
                success: function(data) {
                    if (data !== 0) {
                        Swal.fire({
                            icon: "success",
                            title: "Imported data",
                            text: "Thankyou for importing this file",
                        });

                    } else {
                        Swal.fire({
                            icon: "error",
                            title: "Oops...",
                            text: "Something went wrong!",
                        });
                    }
                },
                error: function() {
                    alert('Error');
                }
            });
        });

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>

<?php
add_action('wp_ajax_nopriv_import_data', 'import_data');
add_action('wp_ajax_import_data', 'import_data');
function import_data()
{

    function upload_image_from_url($thumbnail_url)
    {

        $image_name = basename($thumbnail_url);
        $image_data = file_get_contents($thumbnail_url);
        $upload_dir = wp_upload_dir();
        $image_path = $upload_dir['path'] . '/' . $image_name;
        if ($image_data === false) {
            return new WP_Error('image_fetch_failed', 'Failed to fetch image data');
        }

        $image_saved = file_put_contents($image_path, $image_data);
        if ($image_saved == FALSE) {
            return new WP_Error('Upload failed', 'Failed to upload file');
        }
        return $image_path;
    }

    function insert_image_to_wp_posts($image_path, $post_id)
    {
        $upload_dir = wp_upload_dir();
        $image_url = str_replace($upload_dir['path'], $upload_dir['url'], $image_path);
        $file_info = array(
            'guid' => $image_url,
            'post_mime_type' => mime_content_type($image_path),
            'post_title' => sanitize_file_name(pathinfo($image_path, PATHINFO_FILENAME)),
            'post_status' => 'inherit',
            'post_parent' => $post_id,
        );
        $attachment_id = wp_insert_attachment($file_info, $image_path, $post_id);
        require_once(ABSPATH . 'wp-admin/includes/image.php');
        $attachment_metadata = wp_generate_attachment_metadata($attachment_id, $image_path);
        wp_update_attachment_metadata($attachment_id, $attachment_metadata);
        return $attachment_id;
    }

    $csvFile = get_template_directory() . '/movie_data.csv';


    if (!file_exists($csvFile)) {
        echo 'CSV file not found';
        return;
    }

    if (($handle = fopen($csvFile, 'r')) !== FALSE) {
        $header = fgetcsv($handle);
        while (($data = fgetcsv($handle)) !== FALSE) {
            $post_title = isset($data[1]) ? $data[1] : '';
            $post_date = isset($data[2]) ? $data[2] : '';
            $category = isset($data[3]) ? $data[3] : '';
            $thumbnail_url = isset($data[4]) ? $data[4] : '';
            $post_content = "Movies";
            // Creating post
            $post_data = array(
                'post_title'    => $post_title,
                'post_content'  => $post_content,
                'post_status'   => 'publish',
                'post_type'     => 'movie',
                'post_date'     => $post_date,
            );

            if ($post_data):
                $post_id = wp_insert_post($post_data);
                update_post_meta($post_id, 'category', $category);
                if ($thumbnail_url) {
                    $image_path = upload_image_from_url($thumbnail_url);
                    if (!is_wp_error($image_path)) {
                        $attachment_id = insert_image_to_wp_posts($image_path, $post_id);
                        if (!is_wp_error($attachment_id)) {
                            update_post_meta($post_id, "_thumbnail_id", $attachment_id);
                        }
                    } else {
                        echo "Error while inserting image into WP Posts";
                    }
                } else {
                    error_log('thumbnail url not generated');
                }
            endif;
        }
        fclose($handle);
        echo '1'; // Success
    } else {
        echo '0'; // Failure opening the file
    }
}?>