c# – How to make appsettings.json is configured in project instead of bin folder?

I have this test class code in .NET Core 3.1 which only works when I place the appsettings.test.json in the project bin folder. How do I make it configurable at the project folder instead?

public class ServiceTest
{
    private readonly IConfigurationRoot _configuration;

    public IngestServiceTest_GetNextFileToIngest()
    {
        // Note: appsettings is configured at the bin folder at the moment.
        _configuration = new ConfigurationBuilder().AddJsonFile("appsettings.test.json").Build();
    }
 }