You must use a Steam64ID you can obtain your own using this website: https://steamid.io
Option 1
Step 1: Open your Web Console from within your game panel. In the password section, enter in your Rcon password. This password is found/set in your server.cfg
Step 2: Type in ownerid Steam64ID (with yours) and hit enter. You should receive confirmation that it was successfully added.
Step 3: Type in server.writecfg and hit enter. If you were on the server, you will need to log out and then back in.
Option 2
Step 1: With your server stopped, click the 'Configuration File' button in the control panel.
Step 2: Click the text editor option for the 'users.cfg'
Step 3: On a new line add ownerid Steam64ID replace Steam64ID with the steam64ID of the player you are wanting to give admin to
Step 4: Click save
It should look like
ownerid 76894329123023
If you are wanting to have multiple admins, you would add them each on their own line in the text editor
Example:
ownerid 2345678901234567 "your game name" "admin"
moderatorid 12345678901234567 "your game name" "moderator"
