i integrated the whmcs wp integration + whmcs provisioning

Hi i integrated the whmcs wp integration + whmcs provisioning and now it is seems to be fine, i added a widget - whmcs account - and it is ok if you have account already in whmcs, but there is no options for registration. How can i also set it ? Because i want to push the user to register to the whmcs - and then create thier site here and after it - i can manage them easly from whmcs. - Also i noticed if the user register the site via the wordpress platform - then the user is not generated in the whmcs.
So i think there is only one way to go...

Pls help, thank you