Would like to secure puck.js with a pin code but it fails

Hi
Would like to secure my puck from connection/writing attempts.
Not sure what others use - would like some input.
Was thinking of either using a PIN code if I wanted to do something like connect/write new code, or making it connectable only when the button is pressed.

Tried using this in the onInit function

function onInit() {
  NRF.setSecurity({display : 1, keyboard : 1, mitm : 1, passkey : '1234'});

but get this error

Running onInit()...
BLE Connected, queueing BLE restart for later
Uncaught Error: ERR 0x7 (INVALID_PARAM)
 at line 1 col 72
...mitm : 1, passkey : '1234'});
                              ^
in function called from system

Later I moved the NRF.setSecurity({display : 1, keyboard : 1, mitm : 1, passkey : '123456'});
into the main body of the code and added "56", as it requires 6 characted PIN code.
But I can still connect to it and it does not ask for the code

And worst part is that now I am not able to connect to it =( It connects and then instantly disconnects