If your language is not in the list, you can install font of your language (.OTF or .TTF) from any source like internet (Eg: Google Fonts) . Create a new folder called fonts inside TableNotes folder in your phone storage. The location might differ slightly in your phone. It is generally this -
Then , paste your font file inside fonts folder.
Once, font is installed or pasted in fonts folder, your pdfs will start showing the language of that font.