Shipping Cost Setting

Hello everybody,

we are a small schnapps distillery in germany and have an online shop on WIX. Now we have problems setting the shipping costs.

Here are our shipping costs:

1 bottle = 9, - € per order

3 bottles = 9, - € per order

6 bottles = 10,- € per order

12 bottles = 12, - € per order

These quantities are based on our packaging boxes in stock.

How can I set these "shipping costs by piece" in the WIX online shop? I only find by weight, etc. However, the pieces per order are important to us.

Thanks already for your help.

Best wishes

Alex