Calculate a formula in the module Product

Calculate a formula in the module Product

Hello Community I have a question about Zoho CRM module products, I have a two values.

1 piece price 2 minimum order quantity

I would like to create a fled with the formula unit price * minimum order quantity

($ {} * Produkte.Stückpreis $ {Produkte.Mindestbestellmenge}))

The error message Missing bracket appears.

What am I doing wrong, sorry i'm doing it for the first time.

Thanks in advance