All Cart Items / Buy X, set Price to Amount on matched items rule should be used to set up a price when you sell a batch of products together, but you don't have a specific condition on how to group those products.

1. Go to Items.

2. Press Price Rules.

3. Press + New Price Rule

4. Enter the name of the rule under Name.

5. Select the products or categories that the price rule applies to under PRODUCTS or CATEGORIES and enter the required minimum quantity into 'Buy X' field. 'Max cart QTY' can be used to not apply the rule when the quantity exceeds the value entered into this field.

6. Enter customer group(s) in the field under CUSTOMER GROUP IDS if you want this price rule to apply to specific customer groups. Separate groups with commas.

7. Select which day(s) the price rule is active under DAYS OF WEEK WHEN RULE IS ACTIVE.

8. If the price rule is only active during specific hours, select those hours under HOURS WHEN RULE IS ACTIVE.

9. Fill in fields under START MINUTE and END MINUTE.

10. Select All Cart Items / Buy X, set Price to Amount on matched items under PRICE RULE TYPE.

11. Enter the proper price value under AMOUNT.

12. If you want this price rule to be active during a specific period, select the first day under START DATE and the last day under END DATE.

13. Press Save Changes.