Make sure you have a Premium+ Deezer subscription.
Launch the Deezer app and enter your login details on your Parrot device.
Make sure you enter your Deezer password and not your Facebook password when connecting to your Parrot device.
Your Deezer password was emailed to you when you set up your account through Facebook. If you cannot find your Deezer password click the "forgotten password" button the next time you log in and a new password will be sent to you.