I failed when i trying to post my method from console app. My datas come 0 or null. What is my mistake?

I failed when i trying to post my method from console app. My datas always come 0 or null. I'm sharing my codes and error screenshot.

My Console App:

using MSE.DTO.DTOs.WorkStation;
using Newtonsoft.Json;
using System.Text;

var random = new Random();

var data = new WorkStationRandomValueDTO
{
    WorkStationId = random.Next(1, 100),
    Temperature = (decimal)Math.Round(random.NextDouble() * 100, 2),
    Pressure = (decimal)Math.Round(random.NextDouble() * 2000, 2),
    Status = random.Next(0, 1) == 1
};
var json = JsonConvert.SerializeObject(data);
var content = new StringContent(json, Encoding.UTF8, "application/json");

using (var client = new HttpClient())
{
    var response = client.PostAsync("http://localhost:5002/WorkStationRandom/Post", content).Result;
    if (response.IsSuccessStatusCode)
    {
        Console.WriteLine("Data saved successfully!");
    }
    else
    {
        Console.WriteLine("Failed to save data: " + response.StatusCode);
    }
}

My Mvc Api Controller Code :

using AutoMapper;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using MSE.DataAccess.Context;
using MSE.DTO.DTOs.WorkStation;
using MSE.Entity.Entities.Concrete;
using System.Net;
using System.Text.Json.Serialization;
using System.Web.Http;
using FromBodyAttribute = System.Web.Http.FromBodyAttribute;
using HttpGetAttribute = System.Web.Http.HttpGetAttribute;
using HttpPostAttribute = System.Web.Http.HttpPostAttribute;
using RouteAttribute = System.Web.Http.RouteAttribute;

namespace MSE.Web.Controllers
{
    public class WorkStationRandomController : ApiController
    {
        private readonly ApplicationDbContext _dbContext;
        private readonly IMapper _mapper;
        public WorkStationRandomController(ApplicationDbContext dbContext, IMapper mapper)
        {
            _dbContext = dbContext;
            _mapper = mapper;
        }

        [HttpPost]
        public IHttpActionResult Post(WorkStationRandomValueDTO data)
        {
            if (data != null)
            {
                var workStation = _mapper.Map<WorkStation>(data);
                _dbContext.WorkStations.Add(workStation);
                _dbContext.SaveChanges();

                return Ok();
            }
            else
            {
                return BadRequest("Data cannot be null.");
            }
        }
        [System.Web.Http.HttpGet]
        public string Get()
        {
            return "ok";
        }
    }
}

Here is the picture of my error. My datas always come like this.

My Error

I'm trying to post data from using a console application but my datas come their default values (0 or null).

In your Controller on the post add [FromBody] attribute to your data variable in the declaration.

It chould also be that the serialization that MVC is trying to do from the posted data into your WorkStationRandomValueDTO is failing. If you change it to be a string and do the serialization yourself in code after perhaps you can catch the error.

 [HttpPost]
        public IHttpActionResult Post(string data)
        {
            if (data != null)
            {
               var workStationRandonValue = JsonConvert.DeserializeObject<WorkStationRandomValueDTO>(data);

your Post method is missing the [FromBody] attribute.

Adjust the code as below

[HttpPost]
    public IHttpActionResult Post([FromBody] WorkStationRandomValueDTO data)
    {
        if (data != null)
        {
            var workStation = _mapper.Map<WorkStation>(data);
            _dbContext.WorkStations.Add(workStation);
            _dbContext.SaveChanges();

            return Ok();
        }
        else
        {
            return BadRequest("Data cannot be null.");
        }
    }