That is a regular error many people see when they try to directly download the Windows 11 ISO using the 3rd (bottom) option on that Microsoft web page, use the 2nd (middle) option to download the Media Creation Tool, then open that tool and choose to create a Windows 11 ISO on your C drive, not a bootable USB.
If you are still unable to download the Windows 11 ISO, what language version of the Windows 11 ISO do you need?