The fonts in general CAD are divided into TTF and SHX:

TTF fonts are usually installed directly into FONTs in Windows when installing the system. If TTF fonts are missing, simply download and copy them into the FONTs folder in WINDOWS.

Shx fonts are usually made using specialized software with a suffix of “. SHX”. DWGSee CAD is installed by default in the C:Windows\SysWOW64\shxfont folder in the system directory. If you don’t have one on your computer, download a font file and copy it directly to the shxfont folder in the installation directory.

In DWGSeeCAD, you can also click on the menu Options>Font/xref path to add a custom font directory