Micro:bit v2 examples don't work

Hi everyone.
I'm new here and I would learn to program my microbit v2 with espruino.
So, I've connect my board to Espruino Web IDE. So far so good.
But when I try the examples here it seems that they doesn't work.

For example, I have flash on micro:bit this one

show("1   1\n"+
     "  1  \n"+
     "  1  \n"+
     "1   1\n"+
     " 111 \n");

but nothing happens.

Then I have try with the following one

g = Graphics.createArrayBuffer(5,5,1);
g.flip = function(){show(this.buffer);};

var x = 0;
setInterval(function() {
  x++;
  if (x>50)x=0;
  g.clear();
  g.drawString("Espruino",5-x);
  g.flip();
}, 100);

But nothing.

Instead, when I have try the BLE keyboard example:

var kb = require("ble_hid_keyboard");
NRF.setServices(undefined, { hid : kb.report });

function btnPressed() {
  // Send 'a'
  kb.tap(kb.KEY.A, 0, function() {
    // Followed by capital 'A'
    kb.tap(kb.KEY.A, kb.MODIFY.SHIFT);
  });
}

// trigger btnPressed whenever the button is pressed
setWatch(btnPressed, BTN, {edge:"rising",repeat:true,debounce:50});

It worked (but only when I press A button, not B).

Where am I wrong?

Thank you for your replies!