Getting error when downloading highcharts as png after upgrading node version from 14.x.x to 20.x.x

After upgrading from node version 14.x.x to version 20, we are encountering issues with saving highcharts as PNG files. Previously, everything was functioning properly with node 14 and highcharts v2. I have already attempted several solutions, including running npm install after removing the node_modules folder, as well as updating the lib/server.js file according to [this pull request](https://github.com/highcharts/node-export-server/pull/337). Unfortunately, these approaches have not resolved the issue. Any further suggestions or insights would be greatly appreciated.