How do I to check that text field is Null

Hi I am checking that a textbox does not contain any text,

I tried using regex but 's not working for me.

basically I want to check if a textbox field has text

Can I use in validation

Equals Null

image

It seems like the RegEx should work; but if what you want to do is validate that the text element does not contain any text – the result to be true when empty/null – simply invert the step result.