How to manual disconnect from BLE UART server

Hi,

Espruino beginner here, in need for some help.

I am running code from here:
https://www.espruino.com/BLE+UART

var gatt;
NRF.connect("30:ae:a4:5d:b3:f2 public").then(function(g) {
  gatt = g;
  return gatt.getPrimaryService("6e400001-b5a3-f3­93-e0a9-e50e24dcca9e");
}).then(function(service) {
  return service.getCharacteristic("6e400003-b5a3­-f393-e0a9-e50e24dcca9e");
}).then(function(characteristic) {
  characteristic.on('characteristicvaluech­anged', function(event) {
    console.log("RX: "+E.toString(event.target.value.buffer))­;
  });
  return characteristic.startNotifications();
}).then(function() {
  console.log("Done!");
});

The code:

• connects OK to my BLE UART server (An ESP32 with Arduino BLE server code that repeats sending BLE-UART messages)
  

• displays the data sent by the BLE server in the Espruino IDE.
  
  Data is like:

  RX: D07-06-2020 12.23
  RX: SAAPL,311.01,+11.5%
  RX: SASML,299.45,-4.5%
  RX: Hottentottententente
  RX: Quit
  RX: D07-06-2020 12.23
  RX: SAAPL,311.01,+11.5%
  RX: SASML,299.45,-4.5%
  RX: Hottentottententente
  RX: Quit
  RX: D07-06-2020 12.23
  

But I would like to disconnect from the server when data “Quit” is received.

Something like:

if(buffer.includes("Quit"){
  gatt.disconnect();
}

Have read many things, search the forum, and tried many examples, to no avail.

Who can help along?