ReviewManager.kt

val manager = ReviewManagerFactory.create(context)
val request = manager.requestReviewFlow()
request.addOnCompleteListener { request ->     
    if (request.isSuccessful) {         
        val reviewInfo = request.result         
        val flow = manager.launchReviewFlow(this, reviewInfo)
       flow.addOnCompleteListener { _ ->
         //Continue your application process         
       }     
   }
   else {             
      //Handle the error here     
   }
}