Click on Add to add the post-function to the transition.
Known limitations common to all post-functions:
JMWE shows an error message on the issue view if any error occurs during the execution of the post-function. This message is displayed only if the current user is a Jira administrator.
When you add this post-function to a transition and trigger it, the add-on checks the specified condition against each linked issue of the current issue. If the condition evaluates to any text except false or an empty string, it will remove the issue link. If not, it will not remove the link.