First of all, ensure that you’ve created the units; if not, please refer to:
Zii Inventory-How to Add Units of Measurement – Zii Help Center (ziicloud.com)
Click on “Products” and go to “Product”.
Double click the item that you want to modify.
Or click “Add” to add a new item.
Then, on the item modification page, you can change an item’s minimum unit. (Only when the item has not been sold yet.)
If there are more than one unit for this item, you can go to “Product Price”.
Click “Add” and select a unit.
Set up details and click “Save”.
Then click “Save” when the changes are done.
