Minecraft OP
Operators (OPs) possess a variety of commands essential for moderating a server. Among the commands available to OPs are the ability to alter a player's game mode, adjust server difficulty, provide items, execute kicks and bans, manage whitelisting, and even halt and restart the server. A comprehensive list of commands accessible to OPs can be found here.
Using the Server Console
Note: If you're using Bedrock Edition you will need to also enable cheats on your server.
Login to your control panel and locate your Minecraft Server, once there type in the console, /enter op . Replacing with the player you want to OP.
Giving OP In Game
Granting operator status to a player within the game is more convenient but necessitates existing operator privileges. If you don't have server operator status, you must first elevate your own status by using the console.
Example:Type in the command /op in-game, replacing with the player you intend to op.