What you need to do is select the .NET 7 target in your debug drop down, here:
Also, you can add multiple debug targets, which you can select as well. This is my launchSettings.json, for example which allows one to debug Rhino 8 in either netfx, netcore, and also Rhino 7.
{
"profiles": {
"Rhino-netcore": {
"commandName": "Executable",
"executablePath": "C:\\Program Files\\Rhino 8\\System\\Rhino.exe",
"commandLineArgs": "/netcore",
"environmentVariables": {
"RHINO_PACKAGE_DIRS": "$(ProjectDir)$(BaseOutputPath)$(Configuration)\\"
}
},
"Rhino-netfx": {
"commandName": "Executable",
"executablePath": "C:\\Program Files\\Rhino 8\\System\\Rhino.exe",
"commandLineArgs": "/netfx",
"environmentVariables": {
"RHINO_PACKAGE_DIRS": "$(ProjectDir)$(BaseOutputPath)$(Configuration)\\"
}
},
"Rhino 7": {
"commandName": "Executable",
"executablePath": "C:\\Program Files\\Rhino 7\\System\\Rhino.exe"
}
}
}