add_action(
   'friends_process_feed_item_submit_error',
    function(
        $new_feed,
        $feed
    ) {
        // Your code here.
    },
    10,
    2
);

do_action( 'friends_process_feed_item_submit_error', $new_feed, $feed )

do_action( 'friends_process_feed_item_submit_error', $new_feed, $feed )

do_action( 'friends_process_feed_item_submit_error', $new_feed, $feed )