can't get data-lables in highcharts-export-server on live server

1. i am using highcharts-export-server for export charts and send it to Email in PDF format
2. while i am trying to export that in localy it was working fine, but on live server when i am trying to export all the charts data-lables disappear.

   this is the image from which was exporting from live server.

and here is the image which was exporting locally.

Here is my Code

exports.getPieChartImg = (seriesData, xOrLength, innersize, showLegend, width, height) => {
var chartOpts = {
    chart: {
        type: 'pie',
        width: width,
        height: height,
    },
    plotOptions: {
        pie: {
            innerSize: innersize || 80,
            depth: 25,
            allowPointSelect: true,
            dataLabels: {
                enabled: false,
                format: '<b>{point.name}</b>: {point.percentage:.2f} %'
            },
            showInLegend: showLegend || false,
        },
        series: {
            stacking: 'normal',
            dataLabels: {
                enabled: true,
                color: '#6f6f6f',
                format: '{point.percentage:.2f}',
                crop: false,
                overflow: "none",
            },
            pointWidth: 30,
        }
    },
    legend: {
        labelFormat: '<b>{name}</b> ({percentage:.2f})%',
        useHTML: true,
    },
    series: [{
        data: seriesData
    }]
};

var exportSettings = generateExportSettings(chartOpts, 'Pie');
return generateBase64Chart(exportSettings)
}

function generateExportSettings(chartOpts, constr) {
return {
    // b64: true,
    instr: JSON.stringify(chartOpts),
    noDownload: true,
    constr,
    globalOptions: {
        colors: ['#3BB9DA', '#0F89A8', '#0B8F8B', '#1DB1AD', '#68E3DF', '#FFB469', '#F58B1F', '#D16900', '#FC3C3C', '#FF6666', '#FC8D8D', '#FCC0C0'],
        lang: {
            thousandsSep: ','
        }
    },
    scale: false,
    styledMode: false,
    type: "image/png",
    width: false,
};
 }

function generateBase64Chart(exportSettings) {
return new Promise((resolve, reject) => {
    highchartsExporter.export(exportSettings, function (err, res) {
        if (err) {
            return reject({
                code: '1',
                err,
                msg: 'Error in stock chart',
                exportSettings
            })
        }
        return resolve({
            code: '0',
            msg: 'success',
            data: 'data:image/png;base64,' + res.data,
        })
    });
})
}

from can't get data-lables in highcharts-export-server on live server