Microsoft will retire the Role-Based Access Control (RBAC) application impersonation role in Exchange Online in May 2024. Applications widely use this role in Exchange Online as it enables them to impersonate users in the tenant to perform actions on behalf of the users. You must migrate all your applications from using this role to other options. This article will explore Microsoft’s reasoning behind this move and the current alternatives.
You can read the post on the following link: https://4sysops.com/archives/alternatives-to-rbac-application-impersonation-in-exchange-online/