If you do not have an active email address at which you can receive notifications and messages from ROSTERkey, then you will not be able to follow the normal account activation process.  You will have to contact your supervisor or manager that administers the ROSTERkey system.  They will be able to give you your username and a temporary password and a url link to go to in a Web Browser to activate your account.  The rest of the steps are as described in the article: Activate/Verify Your User Account.