Correct in that it never saw service in the USAAF.
The USSR used the P-63 extensively, and there are official records of it fighting the IJA up to 15 August 1945. (Gordon, Yefim. Soviet Air Power in World War 2. Hinckley, Lancashire, UK: Midland, Ian Allan Publishing, 2008. ISBN 978-1-85780-304-4.) There are no official records of it used on the Eastern front, however the USSR is not able to confirm the fact that they cannot account for the loss of aircraft (over 1000) yet they were not 'used' against the German army. German pilots (who were detailed oriented in their pilot logs) have recorded kills of Soviet P-63's late war. (Hans Ulrich Rudel, "Stuka Pilot", p. 170 ; Black House Ltd, 2012)
It is thought that the Soviet lack of recorded use was political rather than factual to have the USSR aircraft shown in the numbers of downed German planes instead of American Lease-Lend planes. I mean, how do you lose half of your aircraft in two years if you're not flying them against an enemy....?
Food for thought.