404 accessing wp-admin/admin-ajax.php:1 with a plugin

Question

I'm getting a an error prompt using a plugin I created. When I look at the console, it is coming up with POST https://urbanchurn.com/wp-admin/admin-ajax.php 400 (Bad Request). Trying to determine if my code isn't calling ajax correctly or there is something missing between the class and javascript files.

My class file code:

<?php
class WC_Order_Item_Tracker {

    public static function init() {
        add_shortcode('wc_order_item_tracker', array(__CLASS__, 'render_order_lookup'));
        add_action('wp_ajax_update_item_status', array(__CLASS__, 'update_item_status'));
        add_action('wp_ajax_mark_order_complete', array(__CLASS__, 'mark_order_complete'));
        add_action('wp_enqueue_scripts', array(__CLASS__, 'enqueue_scripts'));
    }

    public static function render_order_lookup() {
        if (!empty($_GET['order_id']) && ctype_digit($_GET['order_id'])) {
            $order_id = intval($_GET['order_id']);
            $order = wc_get_order($order_id);
            if ($order) {
                echo '<ul>';
                foreach ($order->get_items() as $item_id => $item) {
                    $picked_up = wc_get_order_item_meta($item_id, '_pickup_status', true);
                    $checked = $picked_up == 'picked_up' ? 'checked' : '';
                    echo '<li>';
                    echo '<input type="checkbox" class="wc-oit-item-checkbox" data-item-id="' . esc_attr($item_id) . '" data-order-id="' . esc_attr($order_id) . '" ' . $checked . '>';
                    echo esc_html($item->get_name());
                    echo '</li>';
                }
                echo '</ul>';
            } else {
                echo '<p>Order not found.</p>';
            }
        } else {
            include WC_OIT_PLUGIN_DIR . 'templates/order-lookup-form.php';
        }
    }

    public static function update_item_status() {
        check_ajax_referer('wc-oit-nonce', 'nonce');
        $orderId = isset($_POST['order_id']) ? intval($_POST['order_id']) : 0;
        $itemId = isset($_POST['item_id']) ? intval($_POST['item_id']) : 0;
        $status = isset($_POST['status']) ? sanitize_text_field($_POST['status']) : '';
        if ($orderId && $itemId && $status) {
            wc_update_order_item_meta($itemId, '_pickup_status', $status);
            wp_send_json_success();
        } else {
            wp_send_json_error('Invalid data provided.');
        }
    }

    public static function mark_order_complete() {
        check_ajax_referer('wc-oit-nonce', 'nonce');
        $orderId = isset($_POST['order_id']) ? intval($_POST['order_id']) : 0;
        if ($orderId) {
            $order = wc_get_order($orderId);
            if ($order) {
                $order->update_status('completed');
                wp_send_json_success();
            } else {
                wp_send_json_error('Invalid Order ID.');
            }
        }
    }

    public static function enqueue_scripts() {
        wp_enqueue_style('wc-order-item-tracker', WC_OIT_PLUGIN_URL . 'assets/css/order-item-tracker.css');
        wp_enqueue_script('wc-order-item-tracker', WC_OIT_PLUGIN_URL . 'assets/js/order-item-tracker.js', array('jquery'), '1.0', true);
        wp_localize_script('wc-order-item-tracker', 'wc_oit_params', array(
            'ajax_url' => admin_url('admin-ajax.php'),
            'nonce' => wp_create_nonce('wc-oit-nonce')
        ));
    }
}

// Initialize the plugin
add_action('plugins_loaded', array('WC_Order_Item_Tracker', 'init'));

My javascript code:

jQuery(document).ready(function($) {
// Event handler for order lookup form submission
    $('#wc-oit-order-form').submit(function(e) {
        e.preventDefault();
        var orderId = $('#order-id').val(); // Assuming the input field has an ID of 'order-id'

        $.ajax({
            url: wc_oit_params.ajax_url,
            type: 'POST',
            data: {
                action: 'render_order_lookup', // The WordPress AJAX action
                order_id: orderId,
                nonce: wc_oit_params.nonce
            },
            success: function(response) {
                // Assuming response is a list of items
                var itemsHtml = '';
                $.each(response.items, function(index, item) {
                    itemsHtml += '<li>' + item.name + ' - Status: ' + item.status + '</li>';
                });
                $('#wc-oit-order-items').html(itemsHtml); // Update the UI with the order items
            },
            error: function() {
                alert('Failed to fetch order items.');
            }
        });
    });

    // Delegated event handler for changing the status of an individual item
    $(document).on('change', '.wc-oit-item-checkbox', function() {
        var checkbox = $(this);
        var itemId = checkbox.data('item-id');
        var orderId = checkbox.data('order-id');
        var status = checkbox.is(':checked') ? 'picked_up' : 'not_picked_up';

        $.ajax({
            url: wc_oit_params.ajax_url,
            type: 'POST',
            data: {
                action: 'update_item_status',
                nonce: wc_oit_params.nonce,
                order_id: orderId,
                item_id: itemId,
                status: status
            },
            success: function(response) {
                if (response.success) {
                    alert('Item status updated successfully.');
                } else {
                    alert('Failed to update item status.');
                }
            },
            error: function() {
                alert('An error occurred while processing your request.');
            }
        });
    });

    // Delegated event handler for marking the entire order as complete
    $(document).on('click', '#wc-oit-mark-order-complete', function() {
        if (confirm('Are you sure you want to mark this order as complete?')) {
            var orderId = $(this).data('order-id');

            $.ajax({
                url: wc_oit_params.ajax_url,
                type: 'POST',
                data: {
                    action: 'mark_order_complete',
                    nonce: wc_oit_params.nonce,
                    order_id: orderId
                },
                success: function(response) {
                    if (response.success) {
                        alert('Order marked as complete.');
                    } else {
                        alert('Failed to mark the order as complete.');
                    }
                },
                error: function() {
                    alert('An error occurred while processing your request.');
                }
            });
        }
    });
});

Any thoughts why it would be hitting an admin-ajax.php 404 error?