Hello, 
 
Thank you for reaching out to us.
 
From the Set up->Advanced section of your form, you can enable the option which allows your respondents to edit the submission at a later time.
 
While this option is enabled, each time the form is submitted, on the Thank You Page of your form our system automatically generated a link that can be accessed to edit the submission. 
 
You can also set up an email notification to go automatically to your respondents with the link they need to access to edit the submission, as long as they have provided their email address on the form.
 
In case you need any other assistance, please let us know.