Hey @JoaoMiguelR -
Are these random people, or someone like an Alumni Employee? If they are Alumni users, then you could utilize the Alumni Service Center which is a more limited portal then say the Employee Center. And you can provide knowledge and catalog items there. Alumni employees would get the sn_hr_sp.hrsp_alumni role which would give them the limited access. Then of course your articles and catalog items would need to be made available to them.
If it is for truly external users that are not in the system, then I think you would need to create an external user self-registration for a portal (Enabling external user self-registration for Service Portal). The users would still need to be created in the system though I believe. I am sure however, that there is more involved in doing this, depending on what you mean by external.
If you are referring to users such as customers, there is a portal for that as well. And they have have their own Knowledge Base "customer service" that can be utilized.
The Alumni have a very basic portal with knowledge and tasks/requests:
Customers have a bit more - but knowledge and support is there:
So there are some options - but if you are looking to create a portal from scratch for 100% external users, you would need to make the portal public.
Here are a couple of SN Docs that may help you as well:
Managing portal access (this page leads to other resources)
Set a Service Portal Page as Public
Hope some of this may help you in your process.
Cheers,
-Rob
