So we know where it was, 12.8 billion years ago.
But how do we know where it is today?
That’s just it... We don’t. For some objects with a discernible relative motion, they can extrapolate where it “should” be, assuming they know all of the variables that could affect its trajectory.
Which, with something the size of the Universe, is impossible.
If we ever come up with a “real-time” map, things would look radically different.
“Not possible” some will say. They are wrong.
Two ways I can think of off the top of my head would be using a quantum level “query”, or sonar analog, to figure out where a mass is.
The other way would be via some kind of gravity scanning technique. Every bit of mass in the Universe has an impact, however small, on every other bit of mass in the same Universe. Figure out how to look at “gravity” directly, and it should tell you where everything is at right now rather than billions of years ago.
These are both hinted at in various theories, although I’m not sure anyones looking in to them as an applied science yet.