You can find and download the UN Samantha font from several reputable font repositories:
Double-click the file and click the button in the preview window. un samantha sinhala font download
: You can find un-samantha.otf in the font index at Lakdiva.org. You can find and download the UN Samantha
Alternatively, drag and drop the file into the C:\Windows\Fonts folder. un samantha sinhala font download