Minecraft / ban not possible?

I want to ban someone from my server. But when I enter / ban (player name) it says "Unknown or incomplete command". Why doesn't it work?

Which server software do you use? Vanilla? Bukkit? Spigot?

You must / ban @player name

but not in Bedrock I think

In the Bedrock no ban goes. You have to enter kick. Then he can no longer join all day. And you have to wait or invite the player.

I use vanilla

I tried @ now, but exactly the same thing was displayed to me…

I have Java Edition. But thanks.

Bedrock or Java?

Java