Users can add to confluence and consume a license if joining project pages in jira project

[Davide Doviti]

Hello,

I have connected a confluence space in the project page section of a Jira Software Project.

If a user, that is not licenced on confluence click on join button in the project page section the result is that the user get access to confluence, being added autmatically to the default confluence users group and spending a new licence. without any admin authorization, I see.

How can I block this feature? 

I'd like to use project pages only for a subset of the jira project users.

Thank you in advance,

Davide