Git bash for Windows Terminal (and preview) - Append json object in your settings.json > profiles > list.

settings.json

{
    "profiles": 
    {
        "list": 
        [
            {
                "commandline": "%PROGRAMFILES%/git/usr/bin/bash.exe -i -l",
                "guid": "{00000000-0000-0000-ba54-000000000002}",
                "icon": "%PROGRAMFILES%/Git/mingw64/share/git/git-for-windows.ico",
                "name": "Git bash",
                "startingDirectory": "%USERPROFILE%"
            }
        ]
    }
}