i do not know how to remove items on wishlist

i started making a wishlist but i dont know how to do the following:

• a button which add/remove items from database when clicked
• display the favourites

@app.route("/add_favourite", methods=["POST"]) # / contact page
def add_favourite():
    if request.method == "POST":
        TablePk = request.form.get("TablePk")
        Id = request.form.get("Id")
        CustomerId = request.form.get("CustomerId")
        dbObject = Database(DB_FILE)
        # Check if that is already added
        # May be remove favourite
        dbObject.addFavourite(TablePk, Id, CustomerId)
        return "<span class='badge text-bg-success'>Added!</span>"

    def addFavourite(self, TablePk, Id, CustomerId):
        cursor = self.connection.cursor()
        query = f"INSERT INTO Favourite ({TablePk}, 'CustomerId') VALUES ({Id}, {CustomerId});"
        #print(query)
        try:
            cursor.execute(query)
            self.connection.commit()
            return True
        except:
            print("Something went wrong")

    $(".favourite-btn").on("click", function (e) {
        e.preventDefault();
        $(".badge").hide("slow");
        
        var button = "#" + $(this).attr('id');
        console.log(button);
        var data = { "TablePk":$(button).attr("data-table"), "Id":$(button).attr("data-id"), "CustomerId":$(button).attr("data-user") }
        console.log(data);
        $.ajax({
            url: "/add_favourite",
            data: data,
            type: "POST",
            success: function (response) {
                $(button).after(response);
                setTimeout(function () {
                    $(".badge").hide("slow");
                }, 3000);
            }

        });
    });

i attempted to create a function to remove the code but it didnt work