1. Login to your server's control panel (https://panel.plox.host/
2. On the left-hand side of your control panel click "console
3. When in the console, type in "op <username>
Replace the username with the user you want to OP. If our username were to be ThatFlick, in the console we would type "op ThatFlick" without the quotation marks.
Please note when executing a command in the console, by default it adds a "/" before the command.
4. Press the "Send" button located at the bottom right or press the "Enter"
key on your keyboard
If you have done this correctly, in the console you will see a response similar to
"[Server] INFO Made ThatFlick a server operator"
You have now successfully "Opped" this username