Custom fields are not visible in API
I created couple custom fields, made them inactive. Then I created 2 which I want to use on invoices and credit memo's, one is Booking ref

When I tried to get these field id I can't
I am using php SDK (newest version)
and when I use
getCompanyPreferences();
method I do not see in payload this field, however I see the first 3 fields which are INACTIVE
How can I get list of active fields so I can get their ids?
Beside when I use quickbook online and I create invoice with this field - it is visible online only and when I pull data for this invoice via api - CustomField property is empty

