Laravel Many To Many Relationships update - laravel-9

Question

I am trying to make Many To Many Relationships with Laravel. but where I'm stuck is, when post is updated, how do I update the pivot table?
posts migration
Schema::create('posts', function (Blueprint $table) {
$table->id();
$table->string('title');
$table->string('body');
$table->timestamps();
});
languages migration
Schema::create('languages', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->string('slug');
$table->timestamps();
});
language_post migration
Schema::create('language_post', function (Blueprint $table) {
$table->id();
$table->foreignId('language_id')->constrained();
$table->foreignId('post_id')->constrained();
$table->timestamps();
$table->boolean('active')->default(false);
});
Language Model
public function posts()
{
return $this->belongsToMany(Post::class)
->withTimestamps();
}
Post Model
public function languages()
{
return $this->belongsToMany(Language::class)
->withTimestamps()
->withPivot('active');
}
PostController
class PostController extends Controller
{
public function index()
{
return Post::with('languages')->get();
}
public function store(Request $request)
{
$post = new Post();
$post->title = $request->title;
$post->body = $request->body;
$post->save();
$post->languages()->attach(explode(',', $request->language));
}
public function show($id)
{
$post = Post::find($id);
$post->languages;
return $post;
}
public function update(Request $request, $id)
{
}
public function destroy($id)
{
$postDelete = Post::find($id);
$postDelete->languages()->detach();
return Post::destroy($id);
}
}