How can Bubble detect or interact with legitimate PDF upload forms on external WordPress sites?

I’m building a workflow in Bubble where I need to work with publicly available PDF upload forms on external WordPress websites (for example, forms created using WPForms, Gravity Forms, or custom file-upload forms).

The goal is not to bypass authentication or upload files without permission. I’m only interested in:

  • Upload forms that are intentionally public

  • Use cases where users are allowed to submit PDFs

  • Legitimate automation or integration scenarios

I’m trying to understand:

  • How to identify whether a WordPress site exposes a public file-upload form

  • Whether Bubble’s API Connector or backend workflows can submit PDFs to such forms

  • How file uploads are typically handled (multipart/form-data, tokens, redirects, etc.)

  • Best practices to stay within security and usage limits when integrating Bubble with external upload forms

If anyone has experience integrating Bubble with third-party file upload forms, examples or guidance would be greatly appreciated.