We are not planning on releasing binaries for Seatbelt, so you will have to compile yourself.
Seatbelt has been built against .NET 3.5 and 4.0 with C# 8.0 features and is compatible with Visual Studio Community Edition. Simply open up the project .sln, choose "release", and build. To change the target .NET framework version, modify the project's settings and rebuild the project.