laravel-medailibrary getFirstMediaUrl("images") not work for joined tables

I have a problem getting media from a joined table in laravel-medailibrary, I used getFirstMediaUrl("images") to get photos from one table and it works, but if I join two or three tables it not work, how can I solve it?

I want to get photos from those posts that shared by a user.

this post table:

this is share_tb table:

this is users table:

this is the media table:

I find my answer after trying some ways:

public function getPosts(Request $request)
{


    $result = [];

    $postID = DB::table("share_tb")->where("user_id", Auth::user()->id)->get();

    foreach ($postID as $id) {

        if (count(Post::where("id", $id->related_id)->get()) > 0) {
            $posts = Post::where("id", $id->related_id)->get();
            foreach ($posts as $post) {

                // $result = $post->getMedia('images');
                array_push($result, [
                    "comment_count" => getTotalComment($post->id),
                    "course_id" => $post->course_id,
                    "id" => $post->id,
                    'post_image' => count($post->getMedia('images')) > 0 ? $post->getMedia('images')[0]->getFullUrl('big') : "",
                    'logo'=>GetCourseLogo::collection(Course::where('course_id',$post->course_id)->get()),
                    "post_author" => $post->post_author,
                    "post_date" => $post->post_date,
                    "post_excerpt" => $post->post_excerpt,
                    "post_modified" => $post->post_modified,
                    "post_parent" => $post->post_parent,
                    "post_title" => $post->post_title,
                    "post_type" => $post->post_type,
                ]);
            }
        }

    }
    return Response()->json($result);

}

and by this resource collection, I get the logo:

class GetCourseLogo extends JsonResource
  {
     public function toArray($request)
       {
          return $this->getFirstMediaUrl('logo');
       }
  }