I have observed that the IV of an option decreases from morning to evening. How to trade options in such a scenario?

At 9:30 in the morning IV of a PUT option is around 30 and by 3 PM it decreases to 27. If market is in my favor (i.e. Nifty is falling), still the PUT price remains the same. And I do not make money. What strategy will help me to take advantage of falling IV from morning to evening.

Please help!

write out of money call options