[Koha-translate] i cant see language list in I18N/L10N preferences

hi, I can't see language list in I18N/L10N preferences in " Home › Administration › System Preferences › Modify system preference 'language' ". only language I can see is English, I want to add Arabic or Persian to this list for changing the language of Opac and Intranet to Arabic. how should I do this ? and which configuration should I do ?