It does not work always on Windows and Mac. This issue will be fixed in next version
You need to open Settings in client and select tab "Blender path"
Choose desired version you need or add through "Add user path" new path. After press to save
Add-оn will be downloaded and installed automatically. To check whether add-on is installed you can in right panel by opening it with Ctrl+R and then open Download manager and select "Enable add-on in Blender"