Issue Preview for Confluence is easy to use, both for administrators and for users. You just have to configure which fields you want to see in the hover, and that's it!
How does it work?
Issue Preview for Confluence retrieves issues information via application links. So all you need to configure is a working application link with a Jira instance. You can read more about this in the Atlassian documentation for application links
It is possible to have links with multiple Jira instances also. Each Jira instance will require a valid license for Issue Preview for Jira in order to show the preview in Confluence.
Setting up the list of fields
The preview can be configured in Jira by project administrators or Jira system administrators, as described here.