Unless you are on a Mac, you cannot use it legally without spending significant money.
It is widely considered the "System Font" for Traditional Chinese on Apple devices. hiragino sans tc free
Search for "Hiragino Sans TC free download" and you'll find a graveyard of sketchy font forums, pseudo-converters, and GitHub repos offering "mirrors." The myth persists because the font ships free with Apple devices (macOS & iOS). If it's on your Mac, shouldn't it be free for everything? Unless you are on a Mac, you cannot
A community-modified version of Source Han Sans with minor adjustments to make it look even more like classic Japanese/Taiwanese gothic styles. Creative Paper-Look Visuals Unless you are on a Mac