I'm just doing Google searches for "MSXML2.ServerXMLHTTP tls 1.2" and seeing what people are saying. Unfortunately we haven't supported ASP for a decade, so I'm out of practice.
One post suggests creating a blank page with this code:
Set objHttp = Server.CreateObject("MSXML2.ServerXMLHTTP.6.0")
objHttp.open "GET", "https://howsmyssl.com/a/check", False
Set objHttp = Nothing
They say that will confirm if your TLS version is correct. This article implies it may be a server configuration issue:
I'd start with that and then maybe bounce another message to the people at UPS and see if it is still a TLS issue, or if that issue was solved.