No, Upwork doesn't accept any crypto. On the top of that, I really advise you to not try to redirect the person outside the site. Or you will get banned from Upwork and perhaps the freelancer too as well. Most refuse for this reason, they're not going to risk their account just because someone wants to make a deal outside .
Agreed and I raised the question in their top rated forum discussion last year that they should try to add crypto payment as an option for freelancer and clients. Ironically most fellow freelancers were against it.
After that, I tried a different approach with my upwork's clients or any other client. after working with them for some time and building a good working relationship. I always slip the idea of Crypto payment casually. ( avoid upwork's chat) A couple of time gave a discount as well. Most of the clients said no because they were not comfortable, but I got lucky with a couple of clients.
you can get very skilled developers in the 
