Yes, you can use ** custom fonts** as long as the software is taking advantage of the built-in Windows fonts. If this is the case, then simply download the font you need and press Windows + R and type fonts. Drag and drop the Belta font into the Fonts window, restart the PC (although it's not necessary) and restart the application.
Choose the Text input tool, then select the font you've just added. Things complicate themselves when the developers use proprietary custom fonts, then you would have to contact them and ask about the availability of Belta font.