SharePoint Add-Ins will retire on April 2, 2026, stopping their functionality. From July 1, 2024, they cannot be installed from the public marketplace, and new tenants lose all usage by November 1, 2024. Organizations should migrate to SharePoint Framework (SPFx) and prepare users and admins accordingly.
Applies to: SharePoint Online
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).