Troubleshooting Code: (KeyError) key :changeset not found

I am following this tutorial . I have followed carefully correcting errors as I go. The app allows you to create a blog post and add comments if you so choose. When I click show Posts, this error I am getting:

[error] #PID<0.581.0> running BlogAppWeb.Endpoint (connection #PID<0.552.0>, stream id 6) terminated
Server: localhost:4000 (http)
Request: GET /posts/1
** (exit) an exception was raised:
    ** (KeyError) key :changeset not found in: %{conn: %Plug.Conn{adapter: {Plug.Cowboy.Conn, :...}, assigns: %{layout: {BlogAppWeb.LayoutView, "app.html"}, post: %BlogApp.Posts.Post{__meta__: #Ecto.Schema.Metadata<:loaded, "posts">, body: "This here is my duck named Mr.Lump My friend Anum is here.", comments: #Ecto.Association.NotLoaded<association :comments is not loaded>, id: 1, inserted_at: ~N[2022-03-17 17:38:18], title: "Look at my Duck, his name is Lump", updated_at: ~N[2022-03-18 17:45:40]}}, body_params: %{}, cookies: %{"_blog_app_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYSjBybkJSX2U0ZHVyalNoLVkzeHhCdlRt.wbQhUfCTv_8d1yKDupYSNN_ewiSgDMVBypamZHRIP1o", "_live_view_todos_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYWWJ1XzE5MnJSSkV6OVl3eVl0cUpvM2pN.NJYDbH-n7JlaQFMHL2_x-T2zhhvyYD6XBmo8GequxP8"}, halted: false, host: "localhost", method: "GET", owner: #PID<0.581.0>, params: %{"id" => "1"}, path_info: ["posts", "1"], path_params: %{"id" => "1"}, port: 4000, private: %{BlogAppWeb.Router => {[], %{Plug.Swoosh.MailboxPreview => ["mailbox"]}}, :before_send => [#Function<0.16477574/1 in Plug.CSRFProtection.call/2>, #Function<2.17183421/1 in Phoenix.Controller.fetch_flash/2>, #Function<0.77458138/1 in Plug.Session.before_send/2>, #Function<0.23023616/1 in Plug.Telemetry.call/2>, #Function<1.46227650/1 in Phoenix.LiveReloader.before_send_inject_reloader/3>], :phoenix_action => :show, :phoenix_controller => BlogAppWeb.PostController, :phoenix_endpoint => BlogAppWeb.Endpoint, :phoenix_flash => %{}, :phoenix_format => "html", :phoenix_layout => {BlogAppWeb.LayoutView, :app}, :phoenix_request_logger => {"request_logger", "request_logger"}, :phoenix_root_layout => {BlogAppWeb.LayoutView, :root}, :phoenix_router => BlogAppWeb.Router, :phoenix_template => "show.html", :phoenix_view => BlogAppWeb.PostView, :plug_session => %{"_csrf_token" => "J0rnBR_e4durjSh-Y3xxBvTm"}, :plug_session_fetch => :done}, query_params: %{}, query_string: "", remote_ip: {127, 0, 0, 1}, req_cookies: %{"_blog_app_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYSjBybkJSX2U0ZHVyalNoLVkzeHhCdlRt.wbQhUfCTv_8d1yKDupYSNN_ewiSgDMVBypamZHRIP1o", "_live_view_todos_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYWWJ1XzE5MnJSSkV6OVl3eVl0cUpvM2pN.NJYDbH-n7JlaQFMHL2_x-T2zhhvyYD6XBmo8GequxP8"}, req_headers: [{"accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"}, {"accept-encoding", "gzip, deflate, br"}, {"accept-language", "en-US,en;q=0.9"}, {"connection", "keep-alive"}, {"cookie", "_live_view_todos_key=SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYWWJ1XzE5MnJSSkV6OVl3eVl0cUpvM2pN.NJYDbH-n7JlaQFMHL2_x-T2zhhvyYD6XBmo8GequxP8; _blog_app_key=SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYSjBybkJSX2U0ZHVyalNoLVkzeHhCdlRt.wbQhUfCTv_8d1yKDupYSNN_ewiSgDMVBypamZHRIP1o"}, {"host", "localhost:4000"}, {"referer", "http://localhost:4000/posts"}, {"sec-ch-ua", "\" Not A;Brand\";v=\"99\", \"Chromium\";v=\"98\", \"Google Chrome\";v=\"98\""}, {"sec-ch-ua-mobile", "?0"}, {"sec-ch-ua-platform", "\"macOS\""}, {"sec-fetch-dest", "document"}, {"sec-fetch-mode", "navigate"}, {"sec-fetch-site", "same-origin"}, {"sec-fetch-user", "?1"}, {"upgrade-insecure-requests", "1"}, {"user-agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.102 Safari/537.36"}], request_path: "/posts/1", resp_body: nil, resp_cookies: %{}, resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"}, {"x-request-id", "Ft5qQ01M_yh3344AAAAE"}, {"x-frame-options", "SAMEORIGIN"}, {"x-xss-protection", "1; mode=block"}, {"x-content-type-options", "nosniff"}, {"x-download-options", "noopen"}, {"x-permitted-cross-domain-policies", "none"}, {"cross-origin-window-policy", "deny"}], scheme: :http, script_name: [], secret_key_base: :..., state: :unset, status: nil}, post: %BlogApp.Posts.Post{__meta__: #Ecto.Schema.Metadata<:loaded, "posts">, body: "This here is my duck named Mr.Lump My friend Anum is here.", comments: #Ecto.Association.NotLoaded<association :comments is not loaded>, id: 1, inserted_at: ~N[2022-03-17 17:38:18], title: "Look at my Duck, his name is Lump", updated_at: ~N[2022-03-18 17:45:40]}}
        (blog_app 0.1.0) lib/blog_app_web/templates/post/show.html.heex:19: anonymous fn/2 in BlogAppWeb.PostView."show.html"/1
        (phoenix_live_view 0.17.7) lib/phoenix_live_view/engine.ex:124: Phoenix.HTML.Safe.Phoenix.LiveView.Rendered.to_iodata/1
        (phoenix_live_view 0.17.7) lib/phoenix_live_view/engine.ex:140: Phoenix.HTML.Safe.Phoenix.LiveView.Rendered.to_iodata/3
        (phoenix 1.6.6) lib/phoenix/controller.ex:772: Phoenix.Controller.render_and_send/4
        (blog_app 0.1.0) lib/blog_app_web/controllers/post_controller.ex:1: BlogAppWeb.PostController.action/2
        (blog_app 0.1.0) lib/blog_app_web/controllers/post_controller.ex:1: BlogAppWeb.PostController.phoenix_controller_pipeline/2
        (phoenix 1.6.6) lib/phoenix/router.ex:355: Phoenix.Router.__call__/2
        (blog_app 0.1.0) lib/blog_app_web/endpoint.ex:1: BlogAppWeb.Endpoint.plug_builder_call/2
        (blog_app 0.1.0) lib/plug/debugger.ex:136: BlogAppWeb.Endpoint."call (overridable 3)"/2
        (blog_app 0.1.0) lib/blog_app_web/endpoint.ex:1: BlogAppWeb.Endpoint.call/2
        (phoenix 1.6.6) lib/phoenix/endpoint/cowboy2_handler.ex:54: Phoenix.Endpoint.Cowboy2Handler.init/4
        (cowboy 2.9.0) /Users/shansiddiqui/Desktop/blog_app/deps/cowboy/src/cowboy_handler.erl:37: :cowboy_handler.execute/2
        (cowboy 2.9.0) /Users/shansiddiqui/Desktop/blog_app/deps/cowboy/src/cowboy_stream_h.erl:306: :cowboy_stream_h.execute/3
        (cowboy 2.9.0) /Users/shansiddiqui/Desktop/blog_app/deps/cowboy/src/cowboy_stream_h.erl:295: :cowboy_stream_h.request_process/3
        (stdlib 3.17) proc_lib.erl:226: :proc_lib.init_p_do_apply/3

This error is coming when I Get Posts, also I cant show posts? Any Idea to go around this