{
"customer":{
    "msisdn":"5321234568"
}

services.AddHttpClient<IBosApiClient, BosApiClient>();

public class BosApiClient : IBosApiClient
{
  private readonly HttpClient httpClient;
  private readonly IConfiguration configuration;

public BosApiClient(HttpClient httpClient, IConfiguration configuration)
{
  this.configuration = configuration;
  httpClient.DefaultRequestHeaders.Authorization = GetAuthenticationHeader();
  httpClient.BaseAddress = new Uri(configuration["API_BASE_URL"]);
  this.httpClient = httpClient;
}

public async Task<CreateCustomerWithOtpResponse> CreateCustomerWithOtp(CreateCustomerWithOtpRequest request)
{
  var requestBody = "{'customer':{'msisdn':'5321234568'}}";
  HttpContent content = new StringContent(requestBody, Encoding.UTF8, "application/json");

  var responseMessage = await httpClient.PostAsync(httpClient.BaseAddress + "customers/otp", content);

  var responseString = await responseMessage.Content.ReadAsStringAsync();

  var response = JsonConvert.DeserializeObject<CreateCustomerWithOtpResponse>(responseString);

  return response;
}
}