Model in subfolder not working

In the controller:

PHP Code:

$companyListModel = new \App\Models\rt3\CompanyListModel(); 


The Models folder has an Rt3 folder with the CompanyListModel.php in it.

PHP Code:

<?php namespace App\Models;

use CodeIgniter\Model;

class CompanyListModel extends Model
{
    protected $table = 'CompanyList';
    protected $DBGroup = 'rt3';

    protected $allowedFields = [
      // database list here
    ];

    protected $primaryKey = "id";

    protected $returnType = 'App\Entities\CompanyList';


} 


Get this error:

Code:

Class 'App\Models\Rt3\CompanyListModel' not found

What am I doing wrong?