Laravel - Relationships - Many To Many Polymorphic Defining The Inverse Of The Relationship

Next, on the Tag model, you should define a method for each of its possible parent models. So, in this example, we will define a posts method and a videos method. Both of these methods should return the result of the morphedByMany method.

The morphedByMany method accepts the name of the related model as well as the "relationship name". Based on the name we assigned to our intermediate table name and the keys it contains, we will refer to the relationship as "taggable":

    morphedByMany(Post::class, 'taggable');
         * Get all of the videos that are assigned this tag.
        public function videos()
            return $this->morphedByMany(Video::class, 'taggable');