Sending a Code to an Email Address in CodeIgniter

I'll give you one example.
You tell us you load a model named Code_model.
This model contains the find_code() function.
But now, you wonder why the line

PHP Code:

$this->find_code(); 


in your controller doesn't work.
That tells me that you don't understand that you have to refer to the model, like this:

PHP Code:

$code = $this->code_model->find_code(); 


The CI documentation is very clear about this concept.