Predefined Environment Variables missing in <domain>.netlify.app

I have several netlify functions that use environment variables that are defined in the netlify.toml file.

When I run a local build with netlify dev, everything works fine. But when everything gets built on the netlify.app domain, those variables are missing.

I know it is not best security practice to do that, not the point.
It should still work according to the documentation.

# Toml File
[build.environment]
    TWILIO_SID = "xxxxxx"
    TWILIO_TOKEN = "yyyyy"
# twilio function
console.log( process.env.TWILIO_SID,  process.env.TWILIO_TOKEN );
# undefined undefined

The documentation says it should just work… not helpful.
My question is how do I enable them to show up on the netlify.app domain?

Environment Variables defined in netlify.toml are not available during the runtime, meaning they can be only accessed during the building of the website. Thus, they are useful only when you’re requiring them in your build process, like client-side JS, etc. However, if you need environment variables in your serverless function calls, you need to add them in the UI.