How can I restrict the form so only approved users can access and submit?

Good morning!!! How can I create a login in my form? Only approved users can access!!!

You can do this by having a short text entry and setting up a conditional logic. 

Here's an example https://www.jotform.com/72724952470965. Enter 1234.

I've done this by following this method: https://www.jotform.com/help/196-Hide-or-Show-Multiple-Fields-at-Once. 

Please note that you cannot use this method to create a login system for your website or to any system. Our Terms of Use prohibits anyone from creating a form that would ask for a login information such as username and password or email and password. If you do, our system might your suspend your account.

I would suggest using a term such as Access Codes or Authentication Codes. Do not mention "Password" in your form, you'll get flag using this term.