Question A plugin can't execute /server command

[TheSasha]

I am using velocity and have a server with AdvancedGUI installed. In the web editor I added an action to click on the command "/send %player% survival" - it writes that it is an unknown command (in the console). I also tried "/server survival" from the player execution - writes that it is an unknown command.

I sent this problem to support and they replied to me:

(use something like HopeCommander for velocity).

I can't find anything like HopeCommander for velocity.....