How do you get and submit a webform in React?
Whenever I ask for a module it gets closed. You got lucky, I guess?

It seems https://www.drupal.org/project/react_webform_backend together with https://github.com/oikeuttaelaimille/gatsby-drupal-webform provides a solution for React/Gatsby. Note:


  This module only provides basic components (textfield, number, textarea etc.) out of the box. More advanced webform components or composite components should be built as custom components. 


And then there's an example.