The website should be open for your location, check your internet connection or if something is blocking you.
Regarding your product, we have published an update, remove the existing version on your computer and install the latest from your account downloads. You will need to register again.
The latest system takes advantage of the new register once, use anywhere licensing system.
https://ctrader.info/d/1630-product-upgrades-to-net-6-mac-os