Nice tip! Btw, if you want a real signed certificate, you can also use Let's Encrypt certificates with an auto-renew client for all types of operating systems (because these free certificates expire after 4 months). You can also use this trick for all kinds of servers requiring ssl encryption when facing the public internet.

Great news @Rob Tweed and @Dmitriy Maslennikov you got IRIS running on a RPi 4 in 64-bit mode! One can use IRIS now for powerful IoT applications too 
 

A very powerful (commercial) module for XLSX generation/manipulation is at https://www.npmjs.com/package/xlsx

Advantage: you could use REST calls to generate and fill your spreadsheet.

HTH,

Ward