As the super user, I am not able to add Zoho desk top to my user

As the super user, I am not able to add Zoho desk top to my user

Currently, I only have the forum application available to my user ID.

I am the Super user and am trying to add Zoho DeskTop.

All other users have a suit of applications which can be removed but not added.

I only have the forum application to choose from.

How can I add Zoho desktop to my user ID?