Ajax message Failed to load resource: the server responded with a status of 404(Not Found)

Use ajax to do front-end and back-end computer interaction, but always report 404 error, everyone answer! Hurry! Thank you very much!

My code is as follows

function  data(){
    $.ajax({
        url:"/c1",
        success:function (data) {
            $(".num h1").eq(0).text(data.confirm)
            $(".num h1").eq(1).text(data.confirm_now)
            $(".num h1").eq(2).text(data.heal)
            $(".num h1").eq(3).text(data.dead)
        }
    })
}

@app.route("/c1")
def get_c1_data():
    data = utils.get_c1_data()
    return jsonify({"confirm":int(data[0]),"confirm_now":int(data[1]),"heal":int(data[2]),"dead":int(data[3])})

<script src="../static/js/controller.js"></script>