For users who cannot dump their own Mii Maker (e.g., they no longer own a 3DS), some emulation front-ends provide workarounds. For instance, Citra can sometimes use a generic Mii database created by the community, though this lacks full editing functionality. Additionally, save editors for specific games can inject custom Mii data without the Mii Maker app. However, these methods are incomplete and not officially supported.
To ensure that Citra Mii Maker runs smoothly on your computer, make sure you meet the system requirements: citra mii maker download