Plugins ChangeSkin

Hello, I try to install the plugins Change Skin :

He can change skin ( very cool )

I see files and i see for 1.9 and +. So i'm happy because my server is in 1.9.

But when i install the plugins : he doesn't work. Just a .jar file in https://aternos.org/files/

And IG when i do /pl nothing about this plugins. I have choose the final version. Thank you for help me

https://dev.bukkit.org/projects/changeskin

@Andreas

I found this :

[14:03:06] [Server thread/ERROR]: Could not load 'plugins/ChangeSkin.jar' in folder 'plugins'

Can i fix this ?

Yes i fix it Thank you !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You can lock

So i want install Citizen but the plugins not appears -_-'

I'm currently looking for plugins for command / chest. This is what the plugins ChestMaster offers but @Andreas refuse me. Do you know a Bukkit plugins that can be used to control / chest?