Hello, thanks for reaching out!
You might have noticed that SonarLint is not marked as compatible with Rider on the JetBrains Plugin Repository.
Actually, although it is possible to install and use SonarLint with Rider, it will only analyze the languages currently supported, and unfortunately these do not include C# yet.
Please also note that support for C# in Rider is one of the current top-voted feature requests for SonarLint. Feel free to add your voice there - support for analysis of C# in Rider is currently not a top priority on our side, and we might reevaluate this position if we feel a strong impact potential.
Finally, and as mentioned in the feature request thread, you can use our C# analyzer as a Nuget package, though its ruleset won’t be synchronized with the one from the server.
Hope this helps!