Or, as Diehard said, the copper stub or nipple might be threaded.
Because if the trap has been soldered on, wouldn’t that have discolored the chrome finish?
So if the trap can be unscrewed, you can screw on a trap adapter.
The slot you cut in the copper might be sealed up when you screw on a brass or copper fitting over it, with plenty of teflon tape.
You might have to cut apart the trap, so you can spin it off the copper threads.
Don’t cut into the tailpiece!