I hope it works! Forgive me if I missed a step - it's been a month or two since I set it up myself 😅

Yes!

• click the middle button at the bottom (hamburger icon)
• under help and support, click settings
• find "read books with..."
• click that, then click kindle when prompted for a preference in where to send books
• you should be redirected to amazon at this point to link your accounts. Sign in and verify.

Yes!! You can also send borrowed ebooks to your kindle if I remember correctly, which is absolutely awesome!