Can I sign in to Skype with Facebook on a mobile device?
No, the sign in with Facebook feature is only supported on Skype for desktop and Skype for Web. If you want to use Skype on a mobile device, you will need to sign in with a Skype Name or Microsoft account.
If you created your account for Skype through Facebook and don’t have a Skype Name or Microsoft account, we recommend that you create a new account for Skype. You can then sign in to the new account on Skype for your mobile device.