Extract all the contents of the downloaded emulator archive into this new folder. Open the folder where citra-qt.exe is located.
The Mii Maker is a built-in system application on the Nintendo 3DS. In emulator setups, "Portable" refers to configuring Citra to run entirely out of a single folder. citra mii maker portable
Open Mii Maker first, create at least one Mii, and save it. Then relaunch the game. The game should now recognize the existing Mii. Extract all the contents of the downloaded emulator