Excise Tax for Oman

Excise Tax for Oman

We are a long time user of Zoho for multiple businesses. We have now started a new business division which is trading of beverages. This product however has an import excise tax (50% of assessed excise value) and sales excise tax (50% of invoice value). However, we don't see an option for this. is there a possibility to add a custom tax structure or enable excise tax in Oman?