なぜUpdate Postが表示されないのか

お世話になります
今下記で勉強しています
https://dotinstall.com/lessons/basic_rails_v3/41820
なぜかUpdate Postが表示されません

Failed to load resource: the server responded with a status of 404 (Not Found)コンソールを確認しました。

posts_controller.rb
1class PostsController < ApplicationController
2
3  # Convention over Configuration (CoC)
4
5  def index
6    @posts = Post.all.order(created_at: 'desc')
7  end
8
9  def show
10    @post = Post.find(params[:id])
11  end
12
13  def new
14    @post = Post.new
15  end
16
17  def create
18    # render plain: params[:post].inspect
19    # save
20    # @post = Post.new(params[:post])
21    # @post = Post.new(params.require(:post).permit(:title, :body))
22    @post = Post.new(post_params)
23    if @post.save
24      # redirect
25      redirect_to posts_path
26    else
27      # render plain: @post.errors.inspect
28      render 'new'
29    end
30  end
31
32  def edit
33    @post = Post.find(params[:id])
34  end
35
36  def update
37    @post = Post.find(params[:id])
38    if @post.update(post_params)
39      redirect_to posts_path
40    else
41      render 'edit'
42    end
43  end
44
45  private
46    def post_params
47      params.require(:post).permit(:title, :body)
48    end
49
50end
51

show.html.erb
1<h2><%= @post.title %></h2>
2<p><%= simple_format @post.body %></p>
3

edit.html.erb
1<h2>Edit Post</h2>
2<%= form_for :post, url: post_path(@post) do |f| %>
3<p>
4  <%= f.text_field :title, placeholder: 'enter title' %>
5  <% if @post.errors.messages[:title].any? %>
6  <span class="error"><%= @post.errors.messages[:title][0] %></span>
7  <% end %>
8</p>
9
10<p>
11  <%= f.text_area :body, placeholder: 'enter body text' %>
12  <% if @post.errors.messages[:body].any? %>
13  <span class="error"><%= @post.errors.messages[:body][0] %></span>
14  <% end %>
15</p>
16
17<p>
18  <%= f.submit %>
19</p>
20<% end %>
21

_form.html.erb
1<%= form_for @post do |f| %>
2<p>
3  <%= f.text_field :title, placeholder: 'enter title' %>
4  <% if @post.errors.messages[:title].any? %>
5  <span class="error"><%= @post.errors.messages[:title][0] %></span>
6  <% end %>
7</p>
8<p>
9  <%= f.text_area :body, placeholder: 'enter body text' %>
10  <% if @post.errors.messages[:body].any? %>
11  <span class="error"><%= @post.errors.messages[:body][0] %></span>
12  <% end %>
13</p>
14<p>
15  <%= f.submit %>
16</p>
17<% end %>
18