How can you hide a field until a person goes in to edit the form

I have a form that requires a supervisor's approval. I would like for the person completing the form to not see the approval/denial field  - only the supervisor.

I have set it up to trigger an email to a supervisor based on which department they choose. I have added text in that email for the supervisor to read, asking them to approve or deny the request, and have added an edit link. 

How can I hide that field until the supervisor goes into the form to approve or deny it? 

I am trying to prevent the people filling out the form from "cheating" and approving the request themselves. 

 here is a link tot he form: https://form.jotformpro.com/62906269707970

It seems you've figured this out using condition and an access code field.

In addition, to make it a bit secure, you may want to show only the  "Manager Access Code" field in edit mode.

Guide:

https://www.jotform.com/help/389-How-to-Show-or-Hide-Fields-on-Edit-URL

So in your condition, you can add:

If Get Form Page URL widget Contains "edit", Show Manager Access Code field

If you have further questions, let us know.