Is there a way to limite categories in the portal for new registered customers?

Hello All,

Our organization is looking to open SysAid to a client and allow external customers to submit tickets via a portal. I've managed to get this setup so a customer can register their own account, however once the account is created for the customer, we'd like to limit the available categories they can select from the catalog.

What I did was setup a new company and limit the catrgories for whoever is a member of this company, however, when a new registered account is created, they do not have the option to select their company and so all categories become visible.

Is there a way to configure registering new customers to specific their company at the time of configuration?

Is there a way to limit categories for new customer accounts, or perhaps force them to select a company? We wish to only allow them the selection of one or two categories, but by default they are able to see all.

I attached a photo of the required fields when registering. Perhaps there is a way to include a mandatory drop-down to select 'Company'? Any help is appreciated.