AWSのS3を利用して画像を保存しようとするとエラーが出ます。(テスト環境）

前提・実現したいこと

railsで写真投稿サイトを作っています。
テスト環境で画像をActiveStorageで保存は出来ました。
AWSのS3に保存しようとするとエラーが起きます。
環境変数のキーを確認しても間違いはありませんでした。
NoMethodError (undefined method `upload' for nil:NilClass): のエラー文で調べてみてもS3に関するものが見当たりませんでした。

追記：こちらの記事投稿後（コードの変更しませんでした。）
新たなエラーになりました。
エラー箇所は同じです。

ーーーーーーーーーー

発生している問題・エラーメッセージ

localエラーメッセージ

NoMethodError in PostsController#create
undefined method `upload' for nil:NilClass

エラーログ

Started POST "/posts" for ::1 at 2021-01-19 13:36:19 +0900
Processing by PostsController#create as HTML
  Parameters: {"authenticity_token"=>"k2SgLUSoiV7b20QUpu+7n8qr/VQ+uqyJAGHJKU5ySWkTQWOFZrWzxy8mxHpkLZbdxOwbpmbwAxd25M7qDTMcJg==", "post"=>{"title"=>"a", "catch_copy"=>"a", "concept"=>"a", "image"=>#<ActionDispatch::Http::UploadedFile:0x00007ffbed1e5438 @tempfile=#<Tempfile:/var/folders/cl/n5bbc7j97mv9y9bp0vxqfftw0000gn/T/RackMultipart20210119-31896-mdy58p.jpg>, @original_filename="kilarov-zaneit-qkhIEUtf9Tc-unsplash.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"post[image]\"; filename=\"kilarov-zaneit-qkhIEUtf9Tc-unsplash.jpg\"\r\nContent-Type: image/jpeg\r\n">}, "commit"=>"投稿"}
  User Load (0.3ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 2 ORDER BY `users`.`id` ASC LIMIT 1
   (0.1ms)  BEGIN
  ↳ app/controllers/posts_controller.rb:16:in `create'
  User Load (0.2ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 2 LIMIT 1
  ↳ app/controllers/posts_controller.rb:16:in `create'
  Post Create (0.8ms)  INSERT INTO `posts` (`title`, `catch_copy`, `concept`, `user_id`, `created_at`, `updated_at`) VALUES ('a', 'a', 'a', 2, '2021-01-19 04:36:19.096316', '2021-01-19 04:36:19.096316')
  ↳ app/controllers/posts_controller.rb:16:in `create'
  ActiveStorage::Attachment Load (1.1ms)  SELECT `active_storage_attachments`.* FROM `active_storage_attachments` WHERE `active_storage_attachments`.`record_id` = 17 AND `active_storage_attachments`.`record_type` = 'Post' AND `active_storage_attachments`.`name` = 'image' LIMIT 1
  ↳ app/controllers/posts_controller.rb:16:in `create'
  ActiveStorage::Blob Create (0.2ms)  INSERT INTO `active_storage_blobs` (`key`, `filename`, `content_type`, `metadata`, `byte_size`, `checksum`, `created_at`) VALUES ('555nja8sgcem7bduc4nvt2f32t4s', 'kilarov-zaneit-qkhIEUtf9Tc-unsplash.jpg', 'image/jpeg', '{\"identified\":true}', 1033632, 'tuEngJU5r7AEBS0tZpsjRg==', '2021-01-19 04:36:19')
  ↳ app/controllers/posts_controller.rb:16:in `create'
  ActiveStorage::Attachment Create (0.8ms)  INSERT INTO `active_storage_attachments` (`name`, `record_type`, `record_id`, `blob_id`, `created_at`) VALUES ('image', 'Post', 17, 17, '2021-01-19 04:36:19')
  ↳ app/controllers/posts_controller.rb:16:in `create'
  Post Update (1.2ms)  UPDATE `posts` SET `posts`.`updated_at` = '2021-01-19 04:36:19.104840' WHERE `posts`.`id` = 17
  ↳ app/controllers/posts_controller.rb:16:in `create'
   (0.8ms)  COMMIT
  ↳ app/controllers/posts_controller.rb:16:in `create'
Completed 500 Internal Server Error in 22ms (ActiveRecord: 5.5ms | Allocations: 12216)


  
NoMethodError (undefined method `upload' for nil:NilClass):
  
app/controllers/posts_controller.rb:16:in `create'

該当のソースコード

yml
1storage.yml
2 amazon:
3  service: S3
4  region: ap-northeast-1
5  bucket: sharegreen
6  access_key_id: <%= ENV['AWS_ACCESS_KEY_ID'] %>
7  secret_access_key:  <%= ENV['AWS_SECRET_ACCESS_KEY'] %>```
8

ruby
1development.rb
2
3 config.active_storage.service = :amazon

ruby
1class PostsController < ApplicationController
2  before_action :set_post, only: [:show, :edit, :update, :destroy]
3  before_action :authenticate_user!, except: [:index, :show]
4  before_action :move_to_index, only: [:edit, :update, :destroy]
5
6  def index
7    @posts = Post.includes(:user).order("created_at DESC")
8  end
9
10  def new
11    @post = Post.new
12  end
13
14  def create
15    @post = Post.new(post_params)
16    if @post.save ←”ここでエラーが出ています”
17      redirect_to root_path
18    else
19      render :new
20    end
21  end
22
23  def show
24  end 
25
26  def edit
27  end
28
29  def update
30    if @post.update(post_params)
31      redirect_to post_path
32    else
33      render :edit 
34    end  
35  end
36
37  def destroy
38    @post.destroy
39    redirect_to root_path
40  end 
41
42  private
43
44  def post_params
45    params.require(:post).permit(:title, :catch_copy, :concept, :image).merge(user_id: current_user.id)
46  end
47
48  def set_post
49    @post = Post.find(params[:id])
50  end
51
52  def move_to_index
53    redirect_to root_path unless current_user == @post.user
54  end
55
56end
57