You can configure a translation provider in Damus under settings -> Translation. I’ve found DeepL to be the highest quality provider but they require a credit card and some information to use the free trial or paid API.
https://translate.nostr.wine uses DeepL when available and GCP Translation API as a backup and lets you pay-as-you-go with sats. After obtaining an API key and purchasing some credits, you can configure it as a LibreTranslate custom server in Damus. 