Support for the Apple Silicon processors is in the current release (July Major Update).
Any add-ins created using C++ will require recompiling so the resulting binary can run on both Intel and Apple processors.
If you're a user of the add-in: check for a new version on the Autodesk App Store or contact the app developer to get a new version.
If you're a developer: see the information from Apple about Building a Universal macOS Binary.
Patrick Rainsberry
Developer Advocate, Fusion 360