ajax post API 403（禁止）

Question

I'm trying to make a login form using ajax post with laravel and the url must pont to the api that provided to me. but keeps on saying 403 for bidden api. they also provides basic Auth username and password. here's my codes bellow. thanks

    $("#login_page").submit(function(e){


        $.ajax({
            type:"POST",

            url:"https://api.samplesample.ph/frontend/login/",
            headers: {
                'Authorization':"Basic **************=",
                "Content-Type": "application/json",
                "cache-control": "no-cache"
            },
            data:$("#login_page").serialize(),//only input
            success: function(response){
                console.log(response);  
            }
        });
        e.preventDefault();
    });