Highcharts export chart exportSettings with svg file

I would like to render map file in the back with a .Net Core project

So, the purpose is to execute Highmaps library on a Javascript middleware, and export the svg file to the "node-export-server".

I have a API which receive from the client some data. I would like to generate the SVG map file with Highmap library and then send to anonother API which will contain a middleware to execute the node module gor the PNG/JPG/... export.

What is the way to pass a svg file to the "node-export-server" module ? I read the associate docs but I didn't found the way... (https://github.com/highcharts/node-export-server/blob/master/README.md)

I would like to pass my SVG file with this sample.

//Include the exporter module
const exporter = require('highcharts-export-server');

//Export settings 
var exportSettings = {
    type: 'png',
    options: {
        title: {
            text: 'My Chart'
        },
        xAxis: {
            categories: ["Jan", "Feb", "Mar", "Apr", "Mar", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        series: [
            {
                type: 'line',
                data: [1, 3, 2, 4]
            },
            {
                type: 'line',
                data: [5, 3, 4, 2]
            }
        ]
    }
};

//Set up a pool of PhantomJS workers
exporter.initPool();

//Perform an export
/*
    Export settings corresponds to the available CLI arguments described
    above.
*/
exporter.export(exportSettings, function (err, res) {
    //The export result is now in res.
    //If the output is not PDF or SVG, it will be base64 encoded (res.data).
    //If the output is a PDF or SVG, it will contain a filename (res.filename).

    //Kill the pool when we're done with it, and exit the application
    exporter.killPool();
    process.exit(1);
});