Once installed the configuration is very simple:
1. Create a Custom Field within Zahara
2. Within the Interface setup in chrome go to Client>Business Unit in the first dropdown select the User Defined Field which should be the same as the description of the custom field created in the previous step. Select Invoice Header and Reference 2 in the other dropdowns and save.
Users will be able now to enter a Reference 2 when posting invoices in Zahara and this information will be populated into the Opera PL Ref 2.