JQuery Ajax请求不起作用

I have an issue with a Ajax request. I used a lot of Ajax and never had problems but in this case it just does not work and I am looking for days into it now and can't find my error.

If you go to: http://sites.ondalocal.com.br/onodera/ Then submit the form with the button that says "Agendar agora!".

By clickung the following code is executed:

$.ajax({
    type : 'POST',
    url : 'http://186.202.184.93/vhosts/sites/wp-content/themes/Onodera_test/onodera.php',
    dataType : 'json',
    data: {
        site : "1", 
        field : "3" 
    },
    success : function(data){
        alert("ok");
    },
    error: function() {
      alert("error");
    }
});

the called php page does not contain errors. but the success function is never called, it always goes to error.

Could anyone please have a quick look at this?

check console.

XMLHttpRequest cannot load http://186.202.184.93/vhosts/sites/wp-content/themes/Onodera_test/onodera.php. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://sites.ondalocal.com.br' is therefore not allowed access. 

Same Origin Policy

wtf