Did you even look at the note at the top of that repo?
Note: We're in the process of deprecating API Port in favor of integrating binary analysis directly into .NET Upgrade Assistant[^]. In the upcoming months, we're going to shutdown the backend service of API Port which will require to use the tool in offline mode. The instructions to use API Port in offline mode can be found here[^].
Follow those instructions and use
the upgrade assistant[
^] instead of a deprecated and not-supported tool.
NB: The upgrade assistant requires .NET 6.0; unlike .NET Framework 4.x, .NET applications will
not automatically use a newer framework version.