1. In the / usr / share / fonts / random file name / truetype
such as: / usr / share / fonts / chinese / truetype.
2. Then put the font file to the newly created font file.
2. Run: mkfontscale
Command prompt: sudo apt install xfonts-utils
3. then execute: mkfontdir, normally does not complain, there will be no output.
4. Finally execute: fc-cache -fv.
