comment_form_must_log_in_after WordPress Action Hook
The comment_form_must_log_in_after hook is used to display a message to the user after they have attempted to submit a comment without being logged in. This message will tell the user that they must be logged in to leave a comment, and provide a link to the login page.
do_action( 'comment_form_must_log_in_after' ) #
Fires after the HTML-formatted ‘must log in after’ message in the comment form.