Download [portable] Revit Extensions For Autodesk Revit 2018 -

If the 2018 version is not visible, use the Autodesk Assistant (the chat bubble in your account portal) and type "Can you help me get a download for Revit 2018 extensions?". If you have an active subscription, they can often populate the download for you.

They may provide a direct download link or FTP access. Otherwise, no legitimate method remains. Download Revit Extensions for Autodesk Revit 2018