Create a rule to validate the checkout based on cart attributes (custom key–value data stored with the cart, such as delivery type, device, app version, etc.).

1. Cart Attribute

Create Cart Attribute Rule:

• Select Cart Attribute: From the Select Rule Type dropdown, choose Cart Attribute to target custom attribute data.
• Enter Attribute Key: Input the attribute name (e.g., Type Of Order).
• Enter Attribute Value: Input the value you want to validate (e.g., Local Delivery).
• Choose the Condition Operator: Select from Contains, Does Not Contain, Empty, or Not Empty to define the validation logic.
• Validation Error Message: Add a custom message that will be shown to customers when the rule condition is met.

Use Cases:

• Block checkout for certain delivery types (e.g., Type Of Order = Local Delivery).
• Restrict checkout based on device (e.g., Device = Mobile).
• Control checkout by app version (e.g., App = 1.10.70).
• Validate custom inputs like gift notes or payment types.