How can I upload a word document that can be signed by multiple people

There is no option for that at the moment. What I can suggest is to convert your Word document into a PDF file, then upload it to Jotform as a SMART PDF FORM.

Here's a guide how-to-use-and-get-the-best-out-of-jotform-smart-pdf-forms.

And from there, you can add multiple signature fields to your form and map it to the imported PDF.

Here's a guide on -how-to-add-an-e-signature-to-your-form.

Please try that and let us know if you need further assistance.