Create a discount code for my own app in google play store [duplicate]

Is it possible with google play store having a non free app that can be downloaded for free (or with a certain discount) if the user provide a promotional code?

How do you get a discount for in app purchases on Google Play?

For discounts and rewards in apps and games, you can tap on the offer to learn more and go into the app or game to redeem it. For discounts on buying books, movies, and games, you can redeem these offers directly on Google Play. The discount will be applied directly in your cart at checkout.

As of now, no you are unable to create a promo code for your app in the Play Store. I recommend at looking at this answer for more details. Please let me know if this answers your question.