Autodesk has a new digital service for getting activation codes easily for eligible products.
Link to the service is here.
Type “Activation code” into the field and click the arrow.
Complete the form by entering your name and email address and basic information of the product. Also the email address of a person who is associated with the serial number is needed. Finally click Submit button. Activation code will appear on the screen.
If problems you can chat with agent or create a support case to Autodesk.