Install xfonts-thai-poonlap by entering the following commands in the terminal:
sudo apt update sudo apt install xfonts-thai-poonlap
Description:
Poonlap Veerathanabutr's bitmap fonts for X
This package provides 14 Thai TIS-620 pseudo-monospace (with zero-width combining characters) and monospace (with full-width combining characters) bitmap fonts for X and Emacs. . These fonts are good for xiterm+thai and Emacs, with complete text styles support for most fonts.
Homepage: https://linux.thai.net/projects/thaixfonts
Version: 1:1.2.7-3
Section: universe/x11