HTC One M9 - Checking for Updates Manually

In Play Store, tap > Settings > Auto-update apps to choose how you want
Google Play to update your apps.
Checking for updates manually
You need an internet connection to check for software updates. Turn on
mobile data or connect to a Wi-Fi network.
Go to Settings, and then tap System update > Check for new system update.
HTC One M9 checks if updates are available.
44 Phone setup and transfer