How to get Additional Data in Appointment+

Hello, since upgrading to last version of A+ I was using the following code to get access to the additional data saved for each appointment (enabling the additional data add-on):

public function _get_appointment_meta($appID) {
$appointments_data = get_option('appointments_data', array());
return empty($appointments_data[$appID]) ? array() : $appointments_data[$appID];

I needed that function because I did not find a public function to call to get access to the data.

Now, with upgrading to A+ last version, the code does no more work.

Can you please tell me if something changed in how the additional data are saved ?
How can I amend the code ?

Thanks for help

Kind regards