1Uninstall the old CallDesk app first (new signature — it won't install over the old one)
2Tap the button above to download, open the file, and allow "Install unknown apps"
3Open the app and grant Microphone / Phone / Storage permissions again
4Log in with your account — you're ready
From now on, whenever the back office updates, the app loads the newest pages automatically — no need to clear cache or reinstall. If a page looks wrong, pull down to refresh; if it persists, come back here and download again.