Problem

In its current state, the Link issues action does not allow for remote issue links. This is to say creating an issue link between an issue in the current cloud instance with another cloud instance connected (can't link issues across sites/instances, only within the same instance)

Any attempts in doing this will result in an error:

Issue does not exist or you do not have permission to see it., You must provide one of 'inwardIssue' or 'outwardIssue'. (issuelinks)

Proposed solution

When using this action there should be an option similar to the UI in Jira to specify if the issue link is local or from a connected instance to allow remote issue linking.