Plugin doesn't work?

Recently I tried installing the plugin on my Pixelmon server, I follow the instruction that is to install the forge version according to what the latest sponge version requires and putting the sponge forge that is of the correct version into the mod folder. Then I tried to install the latest version of this plugin : Lag Remover

When I enter into the world, the plugin does not work as I thought, I also tried doing commands that are related to the plugin but nothing works (I was op btw).

I really need this plugin to work cause the performance in my server has been really poor when there are literally only 3 people in a single server and I have 16gb ram if that even matters.

You are trying to install Bukkit plugin on Sponge server. It will not work.
Choose from this.

Alright thank you very muxh