18. Create Cart Screen
    1. create 2 columns
    2. display items list
    3. create action column
19. Complete Cart Screen
    1. click handler for inc/dec item
    2. click handler for remove item
    3. click handler for checkout
20. Create Signin screen
    1. create sign in form
    2. add email and password
    3. add signin button
21. Connect To MongoDB Database
    1. create atlas mongodb databaase
    2. install local mongodb database
    3. npm install mongoose
    4. connect to mongodb database
22. Seed Sample Data
    1. Create product model
    2. create user model
    3. create seed route
    4. use route in server.js
    5. seed sample product
23. Seed Sample Users
    1. create user model
    2. seed sample users
    3. create user routes
24. Implement Signin API
    1. create signin api
    2. npm install jsonwebtoken
    3. define generate Token
25. complete Signin Screen
    1. npm i react-toastify to show error message
    2. in App.js, we imported ToastContainer and toastify.css
    3. use the userInfo and react context
    4. signoutHandler
    5. in Store.js, read userInfo from from localstorage and 2 new action in the reducer. USER_SIGNIN and USER_SIGNOUT
    6. Most work was signin screen to get user email and password using submitHandler to pass through signin API. if data is coorect we save to localstorage and redirect user to Redirect URL
26. Create Shipping Screen
    1. create form inputs
    2. handle save shipping address
    3. add checkout wizard bar
27. Create Sign Up Screen
    1. create input forms
    2. handle submit
    3. create backend api
28. Implement Select Payment Method Screen
    1. create input forms
    2. handle submit
29. Create Place Order Screen
    1. show cart items, payment and address
    2. handle place order action
    3. create order create api
30. Implement Place Order Action
    1. handle place order action
    2. create order create api
31. Create Order Screen
    1. create backend api for order/:id
    2. fetch order api in frontend
    3. show order information in 2 columns
32. Pay Order By PayPal
    1. generate paypal client id
    2. create api to return client id
    3. install react-paypal-js
    4. use PayPalScriptProvider in index.js
    5. use usePayPalScriptReducer in Order Screen
    6. implement loadPaypalScript function
    7. render paypal button
    8. implement onApprove payment function
    9. create pay order api in backend
33. Display Order History
    1. create order screen
    2. create order history api
    3. use api in the frontend
34. Create Profile Screen
    1. get user info from context
    2. show user information
    3. create user update api
    4. update user info