Http 400 Bad Request Response [Answered]

[Route("api/[controller]")]
  [ApiController]
  public class EventsController : ControllerBase
  {
    [HttpPost]
    public async Task UpdateContacts(List<EventModel> events)
    {
      // Do things here

    }
  }

    public async Task UpdateEvents(int userId, List<EventModel> events)
    {
      var contractResolver = new DefaultContractResolver()
      {
        NamingStrategy = new CamelCaseNamingStrategy()
      };

      var json = JsonConvert.SerializeObject(events, new JsonSerializerSettings
      {
        ContractResolver = contractResolver,
        Formatting = Formatting.Indented
      });

      _httpClient.DefaultRequestHeaders.Clear();
      _httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

      var result = await _httpClient.PostAsJsonAsync($"api/events", json);
    }