To install these extra quality fonts on iOS 15.4, you must use a font installation app to create a configuration profile. Step-by-Step Installation
With iOS 15.4, apple improved how custom fonts are handled, allowing for better rendering and easier installation of high-quality monospace options. Why Choose "Extra Quality" Fixed Space Fonts? ios 154 fixed space font download extra quality
Unlike standard fonts (like San Francisco, the default iOS system font) where letters have different widths (an 'i' is thin, a 'W' is wide), a or monospaced font allocates the same amount of horizontal space to every character. To install these extra quality fonts on iOS 15
：由于Apple官方的字体包可能需要特定流程获取，许多开发者将这些字体打包并分享在GitHub上， vanluom123/SF-Mono-Font 提供了可直接下载的TTF文件集合，方便快捷。 a 'W' is wide)