Program a outlook add-in to process contacts

we require from you to implement an outlook add-in to work well with Outlook 2021 and later

the add-in provides:
- iterate over selected contacts
- provide option to export the contacts
- the exports via are done via REST api

what is required?
- you develop in C# the add-in
- your code can fetch all contact fields and maps it into a contacts DTO class
- the DTO class can be sent via REST api client to a REST api

UI elements:
- button in the ribbon sesion
- context menu for right clicking on mouse
- both provide a settings dialog to define the REST api endpoint

runtime?
- windows 10, 11
- windows server 2019

delivery?
- into our git repository
- clearly structured code in addin parts, ui parts, DTO and rest api client classes
- you show us the working code in your environment
- you install and test it in our clean environment
- we test it also on our clean environment
- deps are defined in nuget
- built with nuget and msbuilt

finally
- after provided tests, we release payments

MS1:
- create a add-in with settings page and all required buttons and menus
- triggering a button, will result into a simple modal dialog popup

MS2:
- implement the rest api client using a public mock api
- client checks if the contact is available already on api server side
- depending on availabbility either the create or update will be implemmented