This is the most critical step. If you download the absolute latest version (v40.x+), it likely won't work on KitKat.
This usually means the APK architecture is wrong. Ensure you downloaded the ARM version, not x86 or ARM64.
: Go to Settings > Security and toggle on Unknown Sources . This allows you to install apps from sources other than the built-in store.
If you own a device running Android 4.4.2, you may have noticed that the Play Store app crashes or refuses to open if you try to update it to the latest version. This is because the newest Google Play Store updates are optimized for Android 10, 11, 12, and beyond.