Client portal set up gives the ability to launch PSA Portal to submit ticket requests from VSA Agents Menu. Opening tickets this way will directly link the ticket in PSA to the user’s machine where the agent is installed and to the user itself. This functionality can be achieved by clicking on the VSA Agent Menu (System Tray Icon) and clicking the contact support menu item. The account associated with the agent will be the account that is linked to the computer regardless of who logs in.

Here is a link to the instructions: https://helpdesk.kaseya.com/hc/en-gb/articles/360015417917-Setting-up-RMM-VSA-Client-portal-access-in-PSA