Is there a way to grant rights in Minecraft?

I downloaded a map from the internet, but I'm in survival mode. However, if I want to change the game mode is in the chat: "You do not have the required authorization to execute this command"

Is there a way to give these rights?

Open for LAN and activate cheats there. Then it goes with the Gamemode.

Try to open the world in the settings via LAN. As far as I remember, you can subsequently get rights and change the game mode.

Thank you!

Possibility Number 1:

Press Esc, open world in LAN, allow cheats: On

Option 2:

Select singleplayer in the menu, click world once, create a copy, allow cheats: On under Activate options

That's how it should work, I think