jQuery Ajax async function don't fired on success

I have code like this:

jQuery("#test_btn").off("click").on("click", function () {
        jQuery.ajax({
                        type: "POST",
                        url: "/api/test/",
                        data: {
                            test: "me"
                        },
                        success: async function (response) {
                            alert("foo");
                        },
                        error: function (e) {
                            console.error(e);

                        }
                    });
        });

why the success function won't print an allert with "foo"? I nedd to use a promise function inside success... but nothing !