There is no possibility to upload your own plugins on Cubedcraft playerservers Commodore640. But you can do a suggestion.
There is no possibility to download other plugins on Cubedcraft playerservers besides the 256 plugins that are already on the dashboard of your playerserver.
Nice server. You should expand the world border to like 1k.
More plugins have that problem. I recommend you to post it in suggestions so it gets more attention. (The suggestions are also getting posted on Discord by the bot, which is more active than the forums).