added the last two models

app/controllers/credentials_controller.rb

@@ -0,0 +1,70 @@
+class CredentialsController < ApplicationController
+  before_action :set_credential, only: %i[ show edit update destroy ]
+
+  # GET /credentials or /credentials.json
+  def index
+    @credentials = Credential.all
+  end
+
+  # GET /credentials/1 or /credentials/1.json
+  def show
+  end
+
+  # GET /credentials/new
+  def new
+    @credential = Credential.new
+  end
+
+  # GET /credentials/1/edit
+  def edit
+  end
+
+  # POST /credentials or /credentials.json
+  def create
+    @credential = Credential.new(credential_params)
+
+    respond_to do |format|
+      if @credential.save
+        format.html { redirect_to credential_url(@credential), notice: "Credential was successfully created." }
+        format.json { render :show, status: :created, location: @credential }
+      else
+        format.html { render :new, status: :unprocessable_entity }
+        format.json { render json: @credential.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # PATCH/PUT /credentials/1 or /credentials/1.json
+  def update
+    respond_to do |format|
+      if @credential.update(credential_params)
+        format.html { redirect_to credential_url(@credential), notice: "Credential was successfully updated." }
+        format.json { render :show, status: :ok, location: @credential }
+      else
+        format.html { render :edit, status: :unprocessable_entity }
+        format.json { render json: @credential.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # DELETE /credentials/1 or /credentials/1.json
+  def destroy
+    @credential.destroy
+
+    respond_to do |format|
+      format.html { redirect_to credentials_url, notice: "Credential was successfully destroyed." }
+      format.json { head :no_content }
+    end
+  end
+
+  private
+    # Use callbacks to share common setup or constraints between actions.
+    def set_credential
+      @credential = Credential.find(params[:id])
+    end
+
+    # Only allow a list of trusted parameters through.
+    def credential_params
+      params.require(:credential).permit(:email, :password)
+    end
+end

app/helpers/credentials_helper.rb

@@ -0,0 +1,2 @@
+module CredentialsHelper
+end

app/models/credential.rb

@@ -0,0 +1,2 @@
+class Credential < ApplicationRecord
+end

app/views/credentials/_credential.html.erb

@@ -0,0 +1,12 @@
+<div id="<%= dom_id credential %>">
+  <p>
+    <strong>Email:</strong>
+    <%= credential.email %>
+  </p>
+
+  <p>
+    <strong>Password:</strong>
+    <%= credential.password %>
+  </p>
+
+</div>

app/views/credentials/_credential.json.jbuilder

@@ -0,0 +1,2 @@
+json.extract! credential, :id, :email, :password, :created_at, :updated_at
+json.url credential_url(credential, format: :json)

app/views/credentials/_form.html.erb

@@ -0,0 +1,27 @@
+<%= form_with(model: credential) do |form| %>
+  <% if credential.errors.any? %>
+    <div style="color: red">
+      <h2><%= pluralize(credential.errors.count, "error") %> prohibited this credential from being saved:</h2>
+
+      <ul>
+        <% credential.errors.each do |error| %>
+          <li><%= error.full_message %></li>
+        <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div>
+    <%= form.label :email, style: "display: block" %>
+    <%= form.text_field :email %>
+  </div>
+
+  <div>
+    <%= form.label :password, style: "display: block" %>
+    <%= form.text_field :password %>
+  </div>
+
+  <div>
+    <%= form.submit %>
+  </div>
+<% end %>

app/views/credentials/edit.html.erb

@@ -0,0 +1,10 @@
+<h1>Editing credential</h1>
+
+<%= render "form", credential: @credential %>
+
+<br>
+
+<div>
+  <%= link_to "Show this credential", @credential %> |
+  <%= link_to "Back to credentials", credentials_path %>
+</div>

app/views/credentials/index.html.erb

@@ -0,0 +1,14 @@
+<p style="color: green"><%= notice %></p>
+
+<h1>Credentials</h1>
+
+<div id="credentials">
+  <% @credentials.each do |credential| %>
+    <%= render credential %>
+    <p>
+      <%= link_to "Show this credential", credential %>
+    </p>
+  <% end %>
+</div>
+
+<%= link_to "New credential", new_credential_path %>

app/views/credentials/index.json.jbuilder

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+json.array! @credentials, partial: "credentials/credential", as: :credential

app/views/credentials/new.html.erb

@@ -0,0 +1,9 @@
+<h1>New credential</h1>
+
+<%= render "form", credential: @credential %>
+
+<br>
+
+<div>
+  <%= link_to "Back to credentials", credentials_path %>
+</div>

app/views/credentials/show.html.erb

@@ -0,0 +1,10 @@
+<p style="color: green"><%= notice %></p>
+
+<%= render @credential %>
+
+<div>
+  <%= link_to "Edit this credential", edit_credential_path(@credential) %> |
+  <%= link_to "Back to credentials", credentials_path %>
+
+  <%= button_to "Destroy this credential", @credential, method: :delete %>
+</div>

app/views/credentials/show.json.jbuilder

@@ -0,0 +1 @@
+json.partial! "credentials/credential", credential: @credential