Linux puskom-ProLiant-DL385-Gen10 5.4.0-150-generic #167~18.04.1-Ubuntu SMP Wed May 24 00:51:42 UTC 2023 x86_64

//etc/fonts/conf.d/65-khmer.conf

 <?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>

<!-- Khmer (km) -->

<alias>
	<family>sans-serif</family>
	<prefer>
		<family>Khmer OS</family>
	</prefer>
</alias>

<alias>
	<family>serif</family>
	<prefer>
		<family>Khmer OS</family>
	</prefer>
</alias>

<alias>
	<family>monospace</family>
	<prefer>
		<family>Khmer OS System</family>
	</prefer>
</alias>

<!-- Khmer (km) ends -->

</fontconfig>