How call to the Api GET method using jquery ajax from other project? [duplicate]

When I call my api get method from Postman client it works and I get json result. I want to get the same result from ajax call. This is a my API URL without any authentication : http://localhost/Web.Api/api/landing

I try this `

$(document).ready(function () {
  const Url = "http://localhost/Web.Api/api/landing";
  
  $(".buttonP").click(function () {
    $.ajax({
      url: Url,
      headers: { 'Access-Control-Allow-Origin': '*' },
      //also I tried the same with the Access-Control-Allow-Methods: GET, POST, PUT, DELETE
      type: "GET",
      dataType: "json",
      success: function (res) {
        console.log(res)
      },
      error: function (e) {
        console.log(e)
      }
    });
  });
});

And get this error: Access to XMLHttpRequest at 'http://localhost/Web.Api/api/landing' from origin 'null' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

And I did some research and find this solution, I added [crossDomain: true, dataType: 'jsonp' ],`

 $(".buttonP").click(function () {
    $.ajax({
      url: Url,
      headers: { 'Access-Control-Allow-Origin': '*' },
      type: "GET",
      crossDomain: true,
      dataType: 'jsonp',
      success: function (res) {
        console.log(res)
      },
      error: function (e) {
        console.log(e)
      }
    });
  });

Then error regarding CORS policy disappear, and the call is reaches to api get method, and in response I see status code 200, but error function is fires and I can't get json result. So what am i doing wrong ?