$config['csrf_protection'] = true;

var HRef = " base_url main/make_register"
    var register_data=  { username : encodeURIComponent(register_username),  email : encodeURIComponent(register_email), password : encodeURIComponent(register_password), first_name : encodeURIComponent(register_first_name), last_name : encodeURIComponent(register_last_name), phone : encodeURIComponent(register_phone), company : encodeURIComponent(register_company), capture : encodeURIComponent(register_capture),  csrf_token_name  : ' csrf_token_hash ' }

    alert( HRef+"  register_data::"+var_dump(register_data) )
    $.ajax({
        timeout: 10000,
        async :false,
        url: HRef,
        type: "POST",
        data: register_data,
        dataType: "json"
    }).done(function(result){
        alert( "result::"+var_dump(result) )
                        ...
    });