How to run a command only in server , without any client

Hello Guys
I have a question , how can i run a command in just server side , i mean just this part

i want to check offline players without running game and this flow is server side , but i don’t know how to run this commands just on server side .
i hope u understanding my question.
sorry for my bad EN ,and thank you for regarding .

Start your command with "ServerExec " to execute a command on server (non shipping builds only).

@see APlayerController::ServerExec