Please set the $presenter property to your presenter path.

[sezohessen]

My Model :

<?php

namespace App\Models;
use App\Presenters\InventoryOutProductPresenter;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Laracasts\Presenter\PresentableTrait;

class InventoryOutProduct extends Model 
{
    use HasFactory,PresentableTrait;
    protected $presenter = InventoryOutProductPresenter::class;
   
}

My Presenter :

<?php
namespace App\Presenters;
use Laracasts\Presenter\Presenter;

class InventoryOutProductPresenter extends Presenter {

    public function product_text_format()
    {
        return $this->title.'('.$this->price_per_qty.')';
    }

}

Call : $model->present()->product_text_format;