I've made a webform with a handler. This handler does a Remote Post towards an API. This API is actually a custom module within the Drupal install which (after some logic) passes all of the preprocessed data towards another API. When that is passed successfully I get a redirect URL back from them, but whatever I use (TrustedRedirectResponse or just normal RedirectResponse) it won't redirect. It just reloads the form.
How to solve this?