I'm trying to make a command to spawn a sedan, so I did /alias add /spawn spawn but when I type /spawn sedan nothing happens and I get this at the console: Server tried to run command ""sedan"", but we blocked it.

The server can't run the majority of console commands on a client, only server-side commands.

Oh, I got it. If someone wants the same thing, here is plugin that allows players with permissions to spawn cars and they don't disappear on restarts: https://umod.org/plugins/car-commander-lite