how to get 'Streak Win Reward' ?

I don't remember what level is that features comes out on your game. Keep in mind that it's a test features and you may not get it at all.

I'm not sure. I used the word "may" mean probably. And also don't be frustrated as it may appear later on. All of us players is testers. To be honest, I once got this helpful system but later on I lost it. Your friend may lost it one day or not. I asked the game support team and this is the answer I got from them why I lost it:

You can check your internet connection to see if it's stable or not. Please follow the steps above to see if it will appear in your game.

And also try to do a soft reset. Log out your game account, then off your phone and wait for 10 seconds. Open your phone and log in your game account to see if it is working.

Don't reinstall your game because delete your game will delete all your useful boosters.

Also, you can try to log in to your game account using a different phone to check ✔️ if it's your phone problem or if it's set from the game server. Sometimes, using a phone that has such features (your friend's phone) and logging in with your game account may help.