Ktor Server for Outlook 365 Mailbox

Looking for an experienced developer proficient in Kotlin to create a reference implementation for a Ktor server. The server's primary purpose is to obtain a long-lived token for accessing a yet-to-be-created Outlook 365 mailbox, with read, write, and send permissions. Ideal skills and experience for the job include: - Exemplary expertise in Kotlin and Ktor server development - Profound knowledge of integrating Outlook 365 Mailbox setup and handling permissions - Understanding methods of acquiring long-lived access tokens An existing mailbox is unavailable; therefore, creation and configuration of a new one will be a part of this project. These specific and necessary skillsets will contribute to the successful execution and delivery of this project. An acceptable solution contains the following: • A Ktor server implementation that is able to obtain a long lived access token using OAuth2/OpenID Connect. • Only use common, maintained libraries. • Must be compatible with Ktor 2.3.x • The authentication flow will be initiated by a web client, for the reference implementation an endpoint/route that does a simple redirect will suffice. • A brief "how to" on how to properly register/setup the application with Microsoft. • Comments in code regarding security considerations will be much appreciated (e.g. "verify A because B", "don't assume X because risk of Y").