I think you need the Greek keyboard. That's easy to get.
HOW TO GET THE GREEK KEYBOARD These links will not only show you how to get the Greek keyboard but also how to find the Greek letters on it, how to add accents etc.
https://www.duolingo.com/comment/22040507 It will also help you learn the alphabet and where to find other
THE GREEK ALPHABET https://www.duolingo.com/comment/22424028
And here is another to help you navigate Duolingo
FAQ - General Questions, Bugs & Reports https://www.duolingo.com/comment/23799672
Some simple hints to get you started:
1.Always read the comments before posting.
- Read the Tips & notes right below the list of lessons on your Homepage
- Read the drop down hints. Pass your cursor over a word and a list of words will appear.
These are the official Duolingo guidelines which you should read. https://www.duolingo.com/guidelines And these will answer lots of questions about how Duo works. https://www.duolingo.com/comment/8000024
If you have questions just ask.