Kill a player by their name?

How can I do something with a player based of their name?
For example, I want to use /kill [playerName]. What’s the correct way?

Hello, why use the name when the user can put special characters.

You can kill someone with his/her id in your server. I use EasyAdmin to do it.
With easy admin you can ban someone, kick someone, freeze someone, slap (Remove some hp) someone. Hope i helped you.

What do you mean?

How can I do that? Also, it seems easier to just do it by their name

download easyadmin and add your self as admin in your server cfg file! here: easyadmin

he means etc: π–†π–œπ–Šπ–˜π–”π–’π–Šπ–‰π–šπ–‰π–Š300
did you understand? you cant write those custom letter characters!

Thank you!
But I want to do this by myself

Thanks!