Hi! I use csharpier, it does the job - I included it as a preliminary check in our CI pipeline for a step of merge requests quality assessment. It is the closest tool I found, that ressembles prettier. You should definitely give it a try.
Kvrocks (under Apache foundation umbrella) is another interesting Redis-compatible alternative, this one is targeting memory and SSD/NVME storage since it is implemented on top of RocksDB. So depending on your needs it may be a more efficient choice compared to Valkey.