Amazon API Generate Access Token and Refresh Token

a)  Log into Amazon Developer Console

https://developer.amazon.com/dashboard

b) Login with Amazon > Create a Security Profile

c) Generate client id and client secret.

d) Add redirect url under web settings as a whitelist redirect url.

e) Generate Authorization Code (One Time)

https://www.amazon.com/ap/oa?client_id=xxxxxxxxxxx&response_type=code&redirect_uri=http://localhost&scope=profile&state=SPECIAL

f) Generate Refresh Token (One Time)

curl --request POST --data "code=xxxxxxxxxxx&client_id=xxxxxxxxxxxx&client_secret=xxxxxxxxxxxxx&redirect_uri=http://localhost&grant_type=authorization_code" https://api.amazon.com/auth/o2/token

g) Generate Access Token from Refresh token (Always)

curl --request POST --data "client_id=xxxxxxxxxxx&client_secret=xxxxxxxxxxx&refresh_token=xxxxxxxxxxxxxxxxxxx&grant_type=refresh_token" https://api.amazon.com/auth/o2/token