Use this event to
...
[EventSubscriber(ObjectType::Codeunit, Codeunit::"MOB WMS Pack Lookup", 'OnPostAdhocRegistrationOnPackagesToShip_OnAddStepsToLicensePlate', '', false, false)]
localprocedure OnPostAdhocRegistrationOnPackagesToShip_OnAddStepsToLicensePlate(var _RequestValues: Record"MOB NS Request Element"; var _Steps: Record"MOB Steps Element");
begin
end;
...