This is a scam and not an Upwork recruiter! Don't do it!
People often pose as recruiters or hiring managers. Their most common scam is to tell you they are sending/supplying software, a mini-office, or a computer. They send a "check" for you to deposit then require you use that money to buy the equipment from their vendor in some way. The check isn't real, they hope you will Western Union your money before you find out. People who fall for this not only lose their money but they often end up with extra fees from their bank. Sadly they target newbies.
We can see that one of our agents have gotten in touch with you via our social media channels. Since it looks like it has already been investigated on, I will recommend that we consolidate all communication via one channel, and in this case, via our social media channel, so that the team can assist you more efficiently.