HTTP 405 API jQuery Ajax PHP

i am trying to add member on myewellness.com

i am using jquery and php on a wordpress website, i have to collect the user's details and add him to myewellness.com this is the link to their api documentation: http://www.mediafire.com/view/pr6s7isht9ihdao/API-Services-Documentation-v2.0-1.pdf

but i am getting this on chrome:

OPTIONS https://api.myewellness.com/api/v1/services/membership/create send @ jquery.js?ver=1.11.2
(index):1 XMLHttpRequest cannot load https://api.myewellness.com/api/v1/services/membership/create. Response for preflight has invalid HTTP status code 405
(index):1509 Failed: [object Object]

and CORS not enabled error on fire fox,

here is my js:

jQuery.noConflict();
    (function( $ ) {
      $(function() {
        $("#register_form").submit(function(){
            console.log("Wellness API Initiated!");

            var api_user_name = $("#user_name").val();
            var api_user_email = $("#user_email").val();
            var api_payment_first_name = $("#payment_first_name");
            var api_payment_last_name = $("#payment_last_name");
            var api_user_password = $("#user_password").val();
            var api_client_address_one = $("#client_address_one").val();
            var api_client_address_two = $("#client_address_two").val();
            var api_client_city = $("#client_city").val();
            var api_client_state = $("#client_state").val();
            var api_client_zip = $("#client_zip").val();
            var api_client_gender = $("#client_gender").val();
            var api_client_home_phone = $("#client_home_phone").val();
            var api_client_cell_phone = $("#client_cell_phone").val();
            var api_client_work_phone = $("#client_work_phone").val();
            var api_client_birth_date = $("#client_birth_date").val();

            $.ajax({
                type: "POST",
                url: "https://api.MYEWELLNESS.com/api/v1/services/membership/create",
                /*headers: {
                    'Authorization':'Basic Vml0YWxhbGVydA==:MTI5OTky',
                    'Content-Type':'application/json'
                },*/
                data: "user_name="+api_user_name+"&password="+api_user_password+"&first_name="+api_payment_first_name+"&last_name="+api_payment_last_name+"&address1="+api_client_address_one+"&address2="+api_client_address_two+"&city="+api_client_city+"&state="+api_client_state+"&country=US&zip="+api_client_zip+"&email="+api_user_email+"&phone="+api_client_home_phone+"&work_phone="+api_client_work_phone+"&cell_phone="+api_client_cell_phone+"&gender="+api_client_gender+"&birthdate="+api_client_birth_date,
                datatype: "json",
                beforeSend: function(xhr) { xhr.setRequestHeader("Authorization", "Basic " +"Vml0YWxhbGVydA==:MTI5OTky"); },
                success: function(msg){
                    console.log("Success: "+msg);
                },
                error: function(error){
                    console.log("Failed: "+error);
                }
            });
            console.log("API Fire Complete!");
            return false;
        });
      });
    })(jQuery);

Their server isn't giving you permission to instruct other people's browsers to access their API.

You shouldn't want to do that anyway - otherwise you will be handing over your API key to all your visitors!

Make the API requests from your server, using PHP, instead. You'll probably want to look at the cURL library to do that.