How to make questions required field?

I have successfully completed a JotForm (Yeah me!) my question is where do I find the button to add the asterisk to indicate an answer to the question is required prior to submission?

It seems you want to make form fields as required fields. Yes it is possible to achieve your requirement by enabling "Required" property of form fields. Please check the screenshot below on how to make form fields as required fied:

Hope this helps.

Do get back to us if you have any questions.