Trying to find a rear derailleur hanger that works with the Shimano Claris R2000 8 speed, on my REI Co-op bike. Have done lots of searching on Shimano's site and Amazon and Google. What am I missing? I think Shimano doesn't have branded/proprietary hangers; if that's the case, how can I find another brand of hanger that I know will fit?
If helpful, the bike specs here: https://www.rei.com/product/106309/co-op-cycles-ard-11w-womens-bike.