So for most of this year the official C# dotnet packages have not worked on Debian 13/Trixie (former "unstable"). For the least couple months I've been entirely unable to tell if Debian 13 is supported.
https://github.com/dotnet/sdk/issues/48973#issuecomment-3326058047
https://github.com/dotnet/core/issues/9649#issuecomment-3218332720
My current experience is that there is no official Debian 13 package or documented support, but the Debian 12 packages work on Debian 13. Microsoft keeps closing github bugs without clarification. Separately, Powershell may or may not be broken.