Get form data and store it into database using AJAX, on submit it gives me Maximum call stack size exceeded

Get form data and store it into database using AJAX, on submit it gives me Maximum call stack size exceeded

$("#addRevenueForm").on("submit", event => {
        event.preventDefault();
        var revenue = $("#revenueTextAdd");
        var month = $("#revenueMonthAdd");
        var unit = $("#revenueUnitAdd");
        $.ajax({
            type: "POST",
            url:"/settings/add_revenue_api/",
            data:{
                revenue:revenue,
                month:month,
                unit:unit,
            },
            dataType: "json",
            success:data => console.log("data =", data),
            error:error => console.log("error = ", error),
        })
    })