This feature is commonly used when multiple entries are made in a form with a lot of common values. By using this feature, you won't need to enter all the information from scratch each time. To set this up, you need to go to:
Redirect & Success Message section
Set Action After Save to Success Message
Turn on Allow users to copy submitted record to a new form toggle.
After submitting the form, you will be redirected to the success message page where you can find a button that enables copying the form submission to a new form.
This feature will only work if the login feature is disabled.