Hi Neha,
In standard we have few item categories for Service Item Quotation:
Check few things if it is not working in GUI as well as in Web UI:
1. In all your Z item category for Quotation, these below settings should be maintained, specially
Relevance for Quotation - "Initially a Quotation"
2. For all item categories, you should maintained the "Item Category Determination".
3. Particular Transaction type should not be blocked or Inactive.
4. Check for Authorization PFCG.
Please check and let us know the status.
Best regards,
Dinesh