Unlike apps from the Play Store that update automatically, apps installed via APK need to be updated in a slightly different way. The process is straightforward though.
When a new update is available, a notification will normally appear inside the ck44app app. Follow the directions from the official channel shown in that notification to get the new APK file.
Download the new APK file and install it the same way as before — you do not need to uninstall the old app first. The new file will install over the existing one and your account details will be kept intact.
Always use the latest version when an update is available — new updates include security improvements and new features. On older versions, certain games or payment options may sometimes stop working.
Remember — only install updates from official channels. If an "update" arrives from an unfamiliar source, do not install it.