Laravel 5.6 Many To Many Polymorphic Relations Insert Not Work - laravel

Question

I'm use laravel 5.6 on this project. Categories value not recorded 'categorizables' pivot table. I check with f12 or bug but I do not get any errors. all of them ok but not recorded pivot table. Where I have
been mistake.
My Blog project sql structure is below
--blogs
id
title
description
...
-- categorizables
category_id
categorizable_id
categorizable_type
Below code belong to Category.php Model
class Category extends Model
{
protected $primaryKey='category_id';
public function blogs(){
return $this->morphedByMany('App\Blog', 'categorizable', 'categorizables', 'category_id');
}
}
Above code belong to Blog.php
public function category($categories)
{
$categories = Blog::buildCatArray($categories);
foreach ($categories as $catName) {
$this->addOneCat($catName);
$this->load('categories');
}
return $this;
}
public function buildCatArray($categories): array
{
if (is_array($categories)) {
$array = $categories;
} elseif ($categories instanceof BaseCollection) {
$array = $this->buildCatArray($categories->all());
} elseif (is_string($categories)) {
$array = preg_split(
'#[' . preg_quote(',;', '#') . ']#',
$categories,
null,
PREG_SPLIT_NO_EMPTY
);
} else {
throw new \ErrorException(
__CLASS__ . '::' . __METHOD__ . ' expects parameter 1 to be string, array or Collection; ' .
gettype($categories) . ' given'
);
}
return array_filter(
array_map('trim', $array)
);
}
protected function addOneCat(string $catName)
{
$cat = Self::findOrCreate($catName);
$catKey = $cat->getKey();
if (!$this->cats->contains($catKey)) {
$this->categories()->attach($catKey);
}
}
public function find(string $catName)
{
return $this->Category::$catName->first();
}
public function findOrCreate(string $catName): Category
{
$cat = $this->find($catName);
if (!$cat) {
$cat = $this->Category::create(['name' => $catName]);
}
return $cat;
}
This my Blog Controller file store class
BlogController.php
public function store(Request $request)
{
$data = new Blog;
$data->title = $request->title;
$data->content = $request->content;
$tags = explode(',',$request->tag);
$categories = explode(',',$request->category);
$data->save();
$data->tag($tags);
$data->category($categories);
}
Best wishes