Convert AMAZON MWS to SPI OAuth help for desktop application

Job ID: 33510744

Budget: $750 – $1,500 USD

I have a Amazon published windows DESKTOP application that is listed on Amazon Developers Apps and uses Amazon MWS API and Amazon is requesting that we migrate to a hybrid Amazon SPI-MWS app. The Amazon SPI uses OAuth. I need to some technical assistance on converting a MWS app to a hybrid SPI-MWS app and implementing OAuth for my windows application.

SEE ATTACHED SCREEN SHOT BEFORE BIDDING.

When I'm editing my app on Amazon's App registration page I don't know what to put into the OAuth Login URI

How to support Amazon OAuth from a windows desktop application?

Amazon MWS to SP-API Migration Guide:
https://developer-docs.amazon.com/sp-api/docs/amazon-mws-to-sp-api-migration-guide

I'm stuck at item # 4 on the migration guide