AJAX handler was not found. 500

An error occurs when trying to send a request

AJAX handler ‘onSubmitContactForm’ was not found. 500

callback.htm

[send]
==

app.js

oc.request('#' + $(e).attr('id'), 'onSubmitContactForm', {
            success: function (json) {
                console.log(json);
            },
            error: function (jqXHR, textStatus, errorThrown) {
                console.table(jqXHR, textStatus, errorThrown);
            }
        });

Plugin.php

class Plugin extends PluginBase
{
    /**
     * pluginDetails about this plugin.
     */
    public function pluginDetails()
    {
        return [
            'name' => 'Обратная связь',
            'description' => 'Обратная связь с отправкой на email',
            'author' => 'del',
            'icon' => 'icon-leaf'
        ];
    }

    /**
     * registerComponents used by the frontend.
     */
    public function registerComponents()
    {

        return [
            'del\Callback\Components\Send' => 'send',
        ];
    }
}

Component file Send.php

class Send extends ComponentBase
{
    public function componentDetails()
    {
        return [
            'name' => 'send Component',
            'description' => 'No description provided yet...'
        ];
    }

    /**
     * @link https://docs.octobercms.com/3.x/element/inspector-types.html
     */
    public function defineProperties()
    {
        return [];
    }

    public function onSubmitContactForm(Request $request){
        return response()->json($request->all());
    }
}

Hello @lomakin

Is the callback.htm file a CMS Partial? If so, you may need to use the {% ajaxPartial %} Twig tag to activate AJAX handlers. Here is a link to the documentation: