Option to use dark mode?

I have no where to post this, so if this is not suitable section, please move this to the right one.
I was wondering where is the option for the dark mode since the bot said and I quoted:

There are lots of ways to customize your experience, such as selecting a dark or light theme.

Any idea?

There have been some changes in the forum but I wonder if they’ve changed the color theme too. I guess someone from the forum will definitely help you. If you do find the answer, please share.

I’ve not found this option on either desktop or mobile. What are you on? Phone or computer?