1. Charge the keyboard fully.
2. Delete the keyboard Bluetooth in your device's Bluetooth listing, restart and repairing. (Bluetooth connection steps: press and hold the Fn+Q/W/E for 3-5 seconds until the Bluetooth indicator light flashes rapidly, indicating that the keyboard has entered Bluetooth pairing mode).
3. Attempt to connect the keyboard to another device via Bluetooth to see if it can work properly.

Press Fn+Q/Fn+W/Fn+E to switch Bluetooth channels.

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.