Passing URL variable from Drupal to Form Assembly

The basic process of passing data to prefill the form is documented at Rendering FormAssembly Forms with Fields Pre-Populated →

To use a query parameter from the request you will also need the Token module → .

Token for Query string value

Insert the token above as the pre-filled value. You can use any token as a prefilled value and they will be dynamically replaced. See /admin/help/token in your site after installing Token for further information.