public void removeGrade(Player player, String groupName) {
        LuckPerms luckPerms = EnviumModeration.getEnviumModeration().luckPerms;
        Group group = luckPerms.getGroupManager().getGroup(groupName);

        // Group doesn't exist?
        if (group == null) {
            player.sendMessage(ChatColor.RED + groupName +  " does not exist!");
        }

        // Load, modify & save the user in LuckPerms.
        luckPerms.getUserManager().modifyUser(player.getUniqueId(), (User user) -> {

            // Create a node to add to the player.
            Node node = InheritanceNode.builder(group).build();

            // Add the node to the user.
            user.data().remove(node);

            // Tell the sender.
            player.sendMessage(ChatColor.RED + user.getUsername() + " is now remove in group " + group.getDisplayName());
        });
    }