Why can't I update the game?

Is the game asking you to update the application, but the store is not showing any update available? If so, you may have to clear the cache of the App Store/Google Play Store or initiate the update manually, following the steps below:

Android via Google Play Store

You can manually update apps individually or in bulk using the Google Play Store app on your mobile device:

1. Open the Google Play Store app 
2. On the top right, find and tap the icon for your profile
3. Tap Manage apps & device. Apps with an update available are labeled "Update available" and  you also have the option to search for a specific app.
4. Locate War Alliance and tap Update.

For the full article, please have a look at: https://support.google.com/googleplay/answer/113412?hl=en

iOS via App Store:

1. Open the App Store
2. On the top of the screen, find and tap the icon for your profile
3. Scroll down to see pending updates and release notes (or scroll up to refresh your profile view) and locate War Alliance
4. Tap Update next to the app icon to update only that app or tap Update All to update all apps with an available update.

For the full article, please have a look at: https://support.apple.com/en-us/HT202180