I cannot locate the envs variable documentation in the docs

Yeah, unfortunately it seems like old docs now have been removed from Google index while new ones are still not really complete, or at least not meaningful structured for several themes.

I’ve wrote a topic about this a few days ago. Directus Docs troubles

Yes, very unfortunate, but we can still access the information through the repo luckily, you can see it here https://github.com/directus/directus/blob/main/docs/self-hosted/config-options.md

Nice find, definitely useful!