How to create pagination on CI4

Hi, I'm having a lot of trouble figuring out how to create pagination on Codeigniter 4.

This is my controller:

PHP Code:

$model = new TestModel();
        
        $data = [
            'website' => lang('Auth.website'),
            'title' => lang('Auth.title_home'),

            'auth' => new \App\Libraries\IonAuth(),
            'model' => new TestModel(),

            'validation' => \Config\Services::validation(),
            'session' => \Config\Services::session(),
            'pager' => \Config\Services::pager(),
            
            'test' => $model->getItem(),
            'categories' => $model->categoryList(),
            'lastComments' => $model->lastComments(5),
        ]; 


This is the model:

PHP Code:

public function getItem($slug = false){
        
        if($slug === false){
            return $this->query('SELECT * FROMa items ORDER BY id DESC')
                ->getResult();
        }

        return $this->asArray()
            ->where(['slug' => $slug])
            ->first();
    } 


While in the view I recall the pagination. As you can see in the model I create the query to retrieve the results, while in the controller I call the model and pager. But I don't know what else to do, I don't understand how and why to use paginate ()