Highcharts export server layout algorithm error - highcharts

Question

I am using the highcharts export server node module to export treemap charts. I'm trying to create a custom layoutAlgorithm. I already have this working on the client side, but when I move the code to the server I get errors. Here's some example code:
import * as exporter from 'highcharts-export-server';
import Highcharts from 'highcharts';
function quadrants(parent, children) {
let width = parent.width / 2;
let height = parent.height / 2;
let areas = [
{
x: parent.x + width,
y: parent.y,
width,
height,
},
{
x: parent.x,
y: parent.y,
width,
height,
},
{
x: parent.x,
y: parent.y + height,
width,
height,
},
{
x: parent.x + width,
y: parent.y + height,
width,
height,
},
];
for (let i = 0; i < children.length; i++) {
areas.push();
}
return areas;
}
// This is the problem line
Highcharts.seriesTypes.treemap.prototype.quadrants = quadrants;
const exportSettings = {
// ...
series: [
type: 'treemap',
levels: [{
level: 1,
layoutAlgorithm: 'quadrants',
}],
],
// ...
}
return new Promise((resolve, reject) => {
exporter.export(exportSettings, (err, res) => {
if (err) reject(err);
resolve(res);
});
});
When I run this code I get the following error
TypeError: Cannot read property 'treemap' of undefined
Is this the incorrect way to set the layout algorithm or is there another way to set a layout algorithm with the highcharts export server?
Thanks