\Bitrix\Main\UI\Extension::load('amcharts4');
\Bitrix\Main\UI\Extension::load('amcharts4_theme_animated');

am4core.ready(function() {
            am4core.useTheme(am4themes_animated);
            var chart = am4core.create("chart1", am4charts.PieChart);
            chart.data = newData;
            ......
            ......
});