You can update your game to the latest version directly through your device's App Store.
Android:
- Open the Google Play Store app
 - Tap the three horizontal lines icon in the top, left-hand corner of the screen
 - Select "My apps & games"
 - Games with an update available are labeled "Update."
 - Locate our game and tap "Update"
 
For more information: https://support.google.com/googleplay/answer/113412?hl=en
iOS:
- Open the App Store, then tap "Today" at the bottom of the screen
 - Tap your profile icon at the top of the screen
 - Scroll down and tap "Update" next to our game
 
For more information: https://support.apple.com/en-us/HT202180