Allow editing of answer to a form

Do you want to allow your users to update their form submissions at a later date? Inside of this guide you can find how to do it:

How to Let Users Update Their Form Submissions at a Later Date

In case that you want to edit submissions, please check this guide:

How to Edit Submissions Made on Your Forms

If I did not understood your question correctly, please explain in more details what are you trying to achieve. 

Let us know if you need further assistance.