how do i update information submitted on the form

If your aim is to edit the submissions of your users, you can do that by following our guide here How-to-Edit-Submissions-Made-on-Your-Forms To sum it up, all you need to do is go to your Submissions page > search for the submission you wish to edit > then update them as needed.

On the other hand, if your aim is to let your users, update/edit their own submissions, that's also achievable by following this guide How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date 

Hope that helped! In case you have further questions, don't hesitate to ask.