shareit/app/Product.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    protected $fillable = ['user_id', 'name', 'url'];

    public function items()
    {
        return $this->hasMany(Item::class);
    }

    public function user()
    {
        return $this->belongsTo(User::class);
    }
}