This filter can be used for changing the comment link icon. It works if the comment link is enabled.
Changelog
Since 7.0.0 version
Parameters
1. $icon (type: string) - the HTML of the comment link
2. $comment (type: WP_Comment object) - the object of the current comment
2. $comment (type: WP_Comment object) - the object of the current comment
Usage
add_filter("wpdiscuz_comment_link_img", function ($html, $comment) {
return "Custom Link";
}, 10, 2);