Using "cracked" serial numbers or keygens from third-party sites carries high risks: High chance of infecting your system.
If you have the physical media or a download folder, you can often find the key within a file named MID.txt or MID01.txt . Opening this file in a text editor like Notepad will display a "Part Number," the first five characters of which typically serve as the product key. Autodesk Autocad 2020 Product Key 001l1 Serial Number