Random plug-in search came up with this result if anyone needs a Clarity engine: https://www.ebay.com/itm/304761733141 Says donor was a 2018 with 30k, but as we know, that's not necessarily engine miles.
Needing one is just a rare occurrence. One poster here had a family member run diesel by accident and replaced the engine. Short of that or running without oil or coolant, it's really hard to need a replacement Clarity engine...