I want open an app that we haved coded without realse it in play store with Google assistant, Is it possible? Cuz when say app name it doesn't recognize our app and go to search section.
Yes, you can open your which is not published on play store with google assistant. I have tried it with my apps and it works fine.
Just make sure your are pronouncing the name correctly. you can also say " Open App Name from my device" so it will not go for search.
I uploaded a small video demonstrating google assistant opening an unpublished app