Users with the permission: "Create, edit, and archive vacancies" or "Publish vacancies" have the ability to add a colleague to the vacancy. You do this in edit mode of the vacancy, and scroll down to Recruitment group.
If you do not have any of these permissions, you need to contact your nearest Super User or Admin (Possibly HR person).
Users with these user rights can grant permissions. You can find names and contact information by clicking on Support ♡ when logged into Grade Varbi.
The support team at Grade Varbi does not have the authority to grant permissions.