Report: Using Filter value on custom event

I am in a scenario where I wants to use filter values inside onload function to run a custom script. Script is running fine however filter values are not passing into custom function.

So whats the best way to pass filter value into javascript function.

var d = new Date();
frappe.query_reports["Custom Report"] = {
    "filters": [
        {
            "fieldname":"from_date",
            "label": __("From Date"),
            "fieldtype": "Date",
            "default": new Date(d.getFullYear(),d.getMonth(),1),
            "reqd": 1
        }
        {
            "fieldname":"to_date",
            "label": __("To Date"),
            "fieldtype": "Date"
            "default": frappe.datetime.get_today(),
            "reqd": 1
        }
    ],
    onload: function(report) {
        report.page.add_inner_button(__("Send Email"), function() {
return frappe.call({                 
              method: "doctype.doctytyp.report.report.function",
              args: {
                    fitlers: report.filters
              },
               callback: function(r) {
                    //console.log(r);
                    frappe.msgprint("Email sent");
                }
            });
        });
    }
}

were you able to make it work?