Travel to India via Zurich


I am an Indian passport holder and resident with an expired H1B visa stamp and have a valid H1B I797 extension (Until Sep. 2025).I am flying in couple of months to India and will get appointment to get my visa stamped.

My question is regarding transit visa. I am looking at have a stopover in Zurich/ Frankfurt

Will i need to apply for a transit visa even if i don’t leave the airport in Frankfurt/Zurich?

Thanks in advance