OpenCart 3没有显示我的模块

I'm fairly new to OpenCart but I know PHP and MVC platforms. I want to make an importer for OpenCart to import some products from a CSV and the photos for them.

However, I've been struggling for the last 2 hours trying to see my module in the admin. I created an admin/controller/module/custom_importer.php:

<?php
class ControllerModuleCustomImporter extends Controller {

}

and a language file admin/language/en-gb/module/custom_importer.php:

$_['heading_title'] = 'Custom Importer';

However, in my admin I can't seem to find the module at all. It's the simplest, emptiest module. What am I doing wrong?

Opencart: Version 3.0.2.0

The path you are using is wrong. Put your file in admin/controller/extension/module/custom_importer.php. Note the class name changes in a corresponding way.

<?php
class ControllerExtensionModuleCustomImporter extends Controller {

}

The language file goes in admin/language/en-gb/extension/module/custom_importer.php.

<?php
$_['heading_title'] = 'Custom Importer';

Now go to Extensions->Extensions and choose Modules. You will see Custom Importer.