How FOPBrowser Wizard can be opened through custom service "testService" instead of out of the box service for the print pick ticket?
Resolving the problem
For achieving this requirement a user has to use the property "yfs.Service_for_Pack_Slip=testService" in the customer_overrides.properties.
This property would override the product actual property for calling the out of the box user service configured and call the custom service "testService" as per the required call.
In case, a user would like to use both the out of the box and the custom service work together then they need to map the parameter with the required service, which would require additional custom code implementation approach for achieving the requirement.