I really appreciate the work of the US Air Force Cambridge Research Laboratories for creating HITRAN. HITRAN is a molecular spectroscopic database used to look molecules in gas and atmosphere. They are the standard archive for transmission and radiance calculations. Without their groundwork we would not be as good at understanding planetary atmospheres.

https://hitran.org/ free after registration

https://hitran.org/media/refs/HITRAN-2020.pdf

HAPI (programming interface manual) https://hitran.org/static/hapi/hapi_manual.pdf

Youtube tutorials https://www.youtube.com/watch?v=NiKuigtFahk&list=PLqOG3cBizT...

It is very easy to use and might help to understand WASP-96 b transmission spectrum. https://stsci-opo.org/STScI-01G7NBXDHYYSVBP2M476PRGG3A.png

https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_...