If you still need to generate this file for an older version like Live 8:
To authorize on a Mac using an .auz file, you are typically performing an offline authorization . This method is used when your music production computer is not connected to the internet or if you are using a legacy version that requires manual activation. How to Authorize with an .auz File Ableton live suite 8 authorize.auz mac
This file is generated by Ableton's server after you provide your computer's unique Hardware Code on their official website. If you still need to generate this file