Bluetooth Name (BT KB 3.0) (BT KB 5.0) Short press FN+1! = Switch to Bluetooth channel 1 and press and hold the 3S code.
Press FN+2@ = to switch to Bluetooth 2 channel and hold down 3S alignment code.
Short press FN+3# = to switch to Bluetooth channel 3, and long press 3S alignment code.
Short press FN+4$= to switch to 2.4G channel, and long press 3S alignment code.
Press FN+5% = to switch to wired mode.
1, the last separate indicator light, charging constant, full off, low power flashing
For complete instructions, here is the link for the same: https://manuals.plus/eweadn/tk950-keyboard-manual