It uses gyroscope sensor for pointing not touch. So if you want to use it , places your hand on the pointer button. A pointer would appear on the screen . Then move your phone in the direction you want the pointer to move to . OR. pretend your phone is a laser pointer, the same way you use a laser pointer is the same way to move the phone.
Sometimes, KDE Connect will not detect a phone. You can restart the services by running killall kdeconnectd and then opening kdeconnect in system settings or running kdeconnect-cli --refresh followed by kdeconnect-cli -l .
It does not rely on the KDE Connect desktop application and will not work with it installed. KDE Connect allows devices to securely share content like notifications or files and other features like SMS messaging and remote control. The KDE Connect team has applications for Linux, BSD, Android, Sailfish, iOS, macOS and Windows.