la_bot_back/app/modules/tgbot/controllers/TgBotRestController.php

<?php

namespace app\modules\tgbot\controllers;

use app\modules\tgbot\models\Tgbot;

class TgBotRestController extends \kernel\app_modules\tgbot\controllers\TgBotRestController
{

    public function actionGetScanBtn(int $id): void
    {
        $dialog = Tgbot::where("dialog_id", $id)->first();
        if ($dialog){
            $this->renderApi([
                'html' => '<a class="btn btn-primary" href="/miniapp/scan">Сканировать</a>',
            ]);
        }
    }

}