Sign in per form

Are you planning to limit the form accessibility? If yes, then it is possible to protect the actual form so that only users who have the link can open it. 

Please check this user guide: Allow-Jotform-to-Be-Filled-out-Only-by-Those-with-a-Special-Link.

You may also do it manually by using the Show and Hide Field conditions. Here's a guide: Hide-or-Show-Multiple-Fields-at-Once.

Hope that helps. Thank you.