Lack of documentation on Java repository stored specs permission to access other repos

Problem

It seems that we don't have any document mentioning the need to set permissions in Java repository stored specs to access the plan repositories present in specs configuration.

When this configuration is missing we have the following error message:

repository '(Bamboo Server's bamboo-specs repo)' is not permitted to use following repository(ies): (Bitbucket Cloud repo used during build time)

com.atlassian.bamboo.exception.RssPermissionException: The plan stored in repository '(bamboo specs repo)' is not permitted to use following repository(ies)...

Suggested solution

This configuration could be mentioned in this page: Enabling repository-stored Bamboo Specs - Atlassian Documentation
Additionally, our tutorial could also have a step to configure a repository. That would be great since the most common scenario in a plan is to have a source code repository attached to it.