Our team is not familiar with these processes. Just the same, I would also recommend that you consult a local accountant for more information on how you can do this properly.
Hopefully, other Community members can chime in on this thread!
If you hire a freelancer, you are not an employer. Independent freelancers are contractors, not employees. That said, I believe there are other hiring models on Upwork that I'm not familiar with that may fall under a different category.