Testcontainers for .Net

I followed Getting started with Testcontainers for .NET at Getting started with Testcontainers for .NET

which works fine but I have a couple of questions:

1 - From where connectionstring to postgres comes from?

2 - Results are ouput to the screen, are they saved somewhere? if not saved, is it possible or is there a flag to save it to results file?

Thanks

It’s two years since I retired from the job where I used DotNet and PostGres, but iirc, GetConnectionString() gets the string from wherever you specify configuration values: Connection Strings - EF Core | Microsoft Learn