I made a new automation rule and set up a trigger that checks the fullness of the "DueDate" field and, depending on the presence of a value inside the field, makes a label in the task. The example in picture 1.
pict. 1

But I encountered a difficulty in another project, where the "Due Date" field is not standard, but is set up through custom fields.

How do I create a rule to check whether this field is full, if it is custom?
The name of this field in the DataBase: customfield_10030
I've tried to make similar designs, but it don't work. Picture 2 and picture 3
pict.2

pict.3
