Prefill forms

I would also like to pre-fill a form. For example, if a user submitted a form previously and would like to go back to edit it or submit again. I would like the form to be prefilled to what the user had submitted. How would I go about doing that? Is there a shortcode or setting? I’m new to php. If the only way to do this is through php, could you please provide a code snippet as an example?

https://www.ads-software.com/plugins/ninja-forms/