How to check the protocol with the new Symfony Expression syntax in a TypoScript condition

I need to check the protocol with the Symfony Expression Langange in TypoScript conditions.

The old syntax is [globalString = IENV:TYPO3_SSL=1]

But in the documentation, there is no mention of TYPO3_SSL.

https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/Conditions/