How to read appsettings.json in xunit test project?

I am trying to write the test cases for one of the method written in MVC controller and in that method I am reading AppSettings.json file. as below

public class MemberController : ControllerBase
{
    IMemberRepository _memberRepository;
    public PayPalKeys payPal;
    public ActiveDirectory activeDirectory;
    private static GraphServiceClient _graphServiceClient;
    public MemberController(IMemberRepository member, IOptions<PayPalKeys> payPal, IOptions<ActiveDirectory> activeDirectory)
    {
        _memberRepository = member;
        this.payPal = payPal.Value;
        this.activeDirectory = activeDirectory.Value;
    }   
    
    private IConfigurationRoot LoadAppSettings()
    {
        try {
            var config = new ConfigurationBuilder()
            .SetBasePath(System.IO.Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", false, true)
            .Build();
            -
            -
            -
        }
        catch(Exception ae){}
    }
}

and the below is my Test code

[Fact]
public void Payment()
{
    var memberRepositoryManagerMock = new Mock<IMemberRepository>();     
    var members = new Members() {};
    var controller = new MemberController(memberRepositoryManagerMock.Object, GetPayPalConfigurationMock().Object, GetActiveDirectoryConfigurationMock().Object);
    var result = controller.MakePayment(members);
}

and that method from controller gives the exception as

The configuration file 'appsettings.json' was not found and is not optional. The physical path is 'F:\API.Test\bin\Debug\netcoreapp2.2\appsettings.json'.

Here I am not understanding that how to mock that "appsettings.json" part in the test case code.