Get file upload requests by user token

This GET endpoint retrieves the list of file upload requests associated with a specific user.
You must provide the user_token in the URL path to identify the user.
Each file upload request includes the file_upload_token, the types of files accepted (files_types_accepted), the time when the request was created, and whether the request is required to proceed with payouts.
The response also includes any referenced attributes (ref_attributes) that link the file request to specific data, such as bank account details or other identifiers.
You can use the optional query parameter only_required to filter results and return only those file upload requests that are mandatory.
The response will be an array of file upload requests, which can then be used to determine what documents need to be uploaded by the user.