C# code sample that shows how to verify a JWT that has been created with ES256 against its corresponding public key
This is not a JWT issued by Auth0, am I right? (Because we only support RS256 and HS256). Which SDK/library are you using?
Did you check the github repos of the respective library you’re using (see a list on https://jwt.io/ for C#) - the github repos should usually also offer a good documentation. I suggest to look there, especially those libraries/SDKs that offer ES256 support.
(Sorry, don’t have a ready-to-go code snippet at hand. Saw there was a similar question on StackOverflow https://stackoverflow.com/questions/40697895/c-sharp-verify-jwt-signed-with-es256-c-sharp-using-bouncycastle but no answer to it)