How to open the Vs debug instance with a default Solution?

[ChristophFromAustria]

I want to try to set up the debug properties of my extension Project to open a solution.
I tried setting up my launchSettings.json to open my solution like this:
{ "profiles": { "Open_ExtensionTestProject": { "commandName": "Executable", "executablePath": "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\Common7\\IDE\\devenv.exe", "commandLineArgs": "/RootSuffix Exp \"C:\\Users\\ch\\source\\repos\\ExtensionTestProject\\ExtensionTestProject.sln\"" } } }

This opened the solution i want to try my extension on but it did not load the debug symbols.
Does anyone now a way how to set this up?

My extension is a VsExtensibility out-of-proc (.net8) project type