Direct user to the google play store to rate the game?

I have created a game and have created a function that allows the user to unlock an item if they rate the game on the android or ios store. How do I direct them to the store so that it opens the actual google play app or apple store app and then know if they have rated the game?

for calling the game in the app store, just call the URL of your game in the app store. The device itself will take care that it opens the page in the store.

For checking, if the game has been rated already, I can't give a hint unfortunately.

But be aware, I heard that google changed the policy that it is not allowed to reward the player for rating the app (not 100% sure, have not double checked it)