Hi @mihamocnik ,
PowerApps portal is an external-facing website, it allows internal and external users to access entity data.
But internal users always means the users within the same organization, but the portal does not discriminate between internal and external users.
It is worth noting that the control of entity permissions(CRUD) in the portal is mainly to see whether the user has logged in and authenticated, all of which are mainly divided into these two types of users: authenticated users and anonymous users.
If the user registers and logs into the portal, he is treated as Authenticated Users, regardless of internal or external users.
If the user doesn't log in, he is treated as Anonymous Users. He would have no permission to access these entities that enable the entity permission.
This might make more sense.
Hope this helps.
Sik