Is STT charged on both buy and sell?

Excuse me, I'm just trying to clarify something about STT charges. Could you please elaborate on whether STT is charged on both the buying and selling of cryptocurrencies or financial assets? I'm interested in understanding the exact nature of these fees and how they impact the overall cost of transactions. It would be helpful if you could also explain any potential exceptions or scenarios where STT might not be applied on both sides of a trade. Thank you for your time and assistance.