I'm not sure what steps you have taken, other than the screen-shots you attached.
Also not sure of your license type..perpetual? subscription?
Here are the (somewhat confusing) instructions for activating 2021 products >instructions<
If this doesn't help, you may want to get in touch with your re-seller, or post in the >licensing and activation forum<
I have Perpetual Activation . I tried that way in your shared link but no effect … I disconnect from internet but I can't see Request code . I have no problem earlier but Strangly from yesterday all Autodesk software like autoCAD 3dmax revit v2020 and v2021 don't give me Request Code and I always confront to Last pic in previous post at the end
no this is correct … I always use this code earlier but in next page don't give me Request code … 😞
Autodesk no longer supports offline activation for 2021 products and later. This is one of the topics covered on this page: https://knowledge.autodesk.com/customer-service/download-install/activate/manual-activation-registra.... In short, you will need to connect your system to the internet in order to complete the online activation process.
@mahyarSOORANI
Were you able to get this resolved?
Also, you shouldn't have a serial number anymore unless you have a Network license. Also looks like the sign in option is missing.
https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/No-Let...
Instructions for Finding the Request Code
Follow the steps exactly as shown in the author's screenshots.
Once you have completed those steps, navigate to the following directory:
Locate the file named ACD20XXen_USRegInfo.html (the file name may vary depending on your Autodesk version).
Open this file, and you will find the required Request Code inside.