How get token from headers to test my controller by mocking the service class - unit-testing

Question

public class AdditionDto
{
public int HttpCode {get; set:}
public string UserName {get; set:}
public int Total {get; set:}
}
public interface IAddtionService
{
AdditionDto AddingTwoNumbers(int input1, int input2, string userName);
}
public class AdditionService : IAdditionService
{
public AdditionDto AddingTwoNumbers(int input1, int input2, string userName)
{
AdditionDto addDto = new AdditionDto()
{
httpCode = 200,
UserName = userName,
Total = input1 + input2
}
return addDto;
}
}
With a controller like this:
public class AdditionController : ControllerBase
{
private readonly IAddtionService _additionService;
public AdditionController(IAddtionService additionService)
{
_additionService = additionService;
}
[HttpGet]
[Authorize(Roles = "Admin")]
[Route("AddtionOfTwoNumbers")]
public IActionResult AddTwoNumbers(int input1, int input2)
{
if (ModelState.IsValid)
{
var token = HttpContext.Request.Headers["Authorization"].ToString();
var tokenbearer = token.Split(' ');
var handler = new JwtSecurityTokenHandler();
var decodedtoken = handler.ReadJwtToken(tokenbearer[1]);
string user = decodedtoken.Claims.Where(x => x.Type == "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name").FirstOrDefault().ToString();
var usr = user.Split(":");
string userName = usr[2].Trim();
var result = _additionService.AddingTwoNumbers(input1, input2,userName);
if (result.Httpcode == 200)
return Ok(result);
else
return StatusCode(500, result);
}
else
return BadRequest();
}
}
When i am trying to conduct xunit test on this api I am getting null at header level.
also I need to mock service method that is also not happening. mostly it is showing null exception even I have passed token in the headers also then I am facing mocking issue at the service method level. could you please help me to mock my service method to test that api through xunit framework....