Hi Alice,

Assuming the field in your MDA object is NULL, this can be set from:

Rules Engine > 3. Setup Action > + Action > Create CTA.

In the bottom section, under criteria, you’d then want to select the field you wish for the trigger to be based, on, select the operator sign to be equals, and check the box designating that the value of the field should be equal to null.

Hope this helps!

Ah! I was looking in the “rule” section. Great, thank you!

You’re welcome!  Rules Engine is pretty complex and there’s so many places to look! I think of ‘Setup Rule’ almost like preparing an object similar to in the MDA, or Data Designer, then ‘Setup Action’ to configure what we want to do, and what will trigger this.  Glad you got it sorted!