At Sale - Discounts - discount codes you can either generate a random code or define a discount code by yourself.
The discount code is created with "add".
Now all you have to do is enter a discount.
If, for example, a 10% discount is to be granted on all items with this code, it works as follows:
Article discount - add a discount and enter the percentage at discount.
The previously created discount code must then be selected at discount codes.