1. Directly press the Esc button to get a "`".
2. Press Shift + Esc button to get a "~".
3. Press the Fn + Esc button to open the home page.
4. Press the Fn + Shift + Esc button to get the Esc function.

By resetting the keyboard Bluetooth and entering the pairing mode for the desired channel, you should be able to establish a connection.

Since the XK03 keyboard does not have a separate Del button, the XK03 keyboard does not support the Ctl+Alt+Del shortcuts.