I have more or less the same question as posted here: https://community.nintex.com/thread/2994
The above settings are on the checkbox itself > It is set to NO (empty) by default.
When submitting the form and the Terms & Contions is not ticket;
then it should display "please read / agree to the Terms & Condition" with a red square:
I have also tried with a validation Rule:
yet not working / validating
Here is another similar topic: https://community.nintex.com/thread/2613
but cannot seem to figure out how to make the checkbox a requirement!
I am out of ideas ...