(Note: The format usually appears as a number followed by letters, often formatted as 128I1 in documentation.)
When you initially purchased the software, Autodesk sent a confirmation email. This email contains your Serial Number, Product Key, and the link to download the software. Searching your inbox for terms like "Autodesk," "3ds Max," or "Order Confirmation" is often the quickest way to find this information. 3ds max 2017 product key