Make sure you are logged into your own Facebook in the web browser of your device as well as your Facebook app if you have this downloaded. Then, open Flutter: Starlight and then tap the friends icon. Tap connect and then tap connect under the Facebook icon, you will then be redirected to Facebook, all you need to do is tap "OK".
You will then be directed back to Starlight and will receive a green confirmation message. If your Facebook friends have also connected and updated, they will also appear in your friends list and you can now send gifts!