Go to Settings > Security and enable "Install from Unknown Sources" for your browser or file manager.
Some features, like call recording, are geo-locked and may not appear depending on your country's privacy laws. realme ui 50 dialer apk latest version upd upd
It sounds like you're asking for a for the Realme UI 5.0 Dialer (the phone app) in its latest APK version. Go to Settings > Security and enable "Install