How can we check whether a value is NULL or blank in a CPQ rule in Redwood UI?

Summary:

How can we check whether a value is NULL or blank in a CPQ rule in Redwood UI?

Content (please ensure you mask any confidential information):

In the Jet UI, we were able to configure a rule condition where the attribute value equals blank. However, in the Redwood UI, the Value field for the rule condition is mandatory, and it does not allow us to leave the value blank. Could you please advise how we should check for a blank or NULL value in this case?

Version (include the version you are using, if applicable):

26B patch8

Code Snippet (add any code snippets that support your topic, if applicable):