My world rain command code

Rain command: /weather rain, the specific weather command is as follows:

Command when the rain stops: /weather clear

Thunderstorm command: /weather thunder

Sunny day: /weather sun

Snowy day: /weather storm

Enter commands

After entering the game, after entering any commands and cheats, There is no permission. How can I obtain this permission? Entering the /op name is of no use. Even this command does not have permission. Press the ESC key, click "Open to LAN" and then turn on "Allow cheating", then click "Create a LAN", and then you can enter.