To enable debug mode, change the value in config APP_DEBUG to true. This will enable many options. Also, you can select some of this function in [debug] option in config.
In debug mode, all errors will be logged into error.log and saved to DB.
In debug mode, all visits will be logged into access.log and saved to DB.
You can enable Tracy extension by creating file with following code:
<?php require_once $_SERVER['DOCUMENT_ROOT']."/../vendor/autoload.php"; use Tracy\Debugger; Debugger::enable(!($GLOBALS["CONFIG"]["basic"]["APP_DEBUG"] == "1"));
and by adding that file into the config:
[addintional_loader_files_before] file = tracy.php