How can I upload a form from a website?

I am assuming you want to embed the form to your website. If yes, please follow this guide: https://www.jotform.com/help/34-Adding-a-Form-to-a-Web-Page

If you want to add a File Upload field to your form, please check this link: https://www.jotform.com/help/332-How-to-Create-File-Upload-Forms

If I misunderstood your questions, please let us know. Thank you.