Yes, I know. A Zendesk blog that uses a static FAQ instead of Zendesk Guide goes against all logic. But then again, Logic is the beginning of wisdom, not the end of it.
We refer a lot to authenticating to the Zendesk API. You can find more info about this in the following Zendesk Support article:
Some of the automations we build contain example code for Cloudflare Workers. You can use Google Cloud Functions, AWS Lamba or Azure Cloud Functions if that's your cup of tea. I prefer Cloudflare cause it's cheap (or free), doesn't have a lot of overhead and Zendesk already uses Cloudflare for caching it so it makes conversations with my customers easier.