Mine Composer Autoload PSR-4 is not working

Question

I have a problem with my composer and I don't know where to run. I took several classes on how to do this, but my composer doesn't work well. It manages to import my database connection class, but the rest of the classes, in other files, cannot.

My composer.json it is like this:

{
  "autoload":{
    "psr-4":{
      "Src\\": "src/"
    }
  }
}

The namespace in the file looks like this:

namespace Src\Model;

And the instance happens this way:

$instance = new \Src\Model\CrudUsuario();

The error is as follows:

Fatal error: Uncaught Error: Class 'Src\Model\CrudUsuario' not found in C:\wamp64\www\Src\Controller\crud_usuario.php on line 79