Código Delphi [-]
Adapter := TJBluetoothAdapter.JavaClass.getDefaultAdapter;
Adapter.enable;
JStringToString(Adapter.getName);

Código Delphi [-]
unit MainForm;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.StdCtrls;

type
  TForm1 = class(TForm)
    ButtonPrint: TButton;
    procedure ButtonPrintClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

procedure TForm1.ButtonPrintClick(Sender: TObject);
var
  Intent: JIntent;
begin
  // Crear un Intent para enviar datos a la impresora
  Intent := TJIntent.Create;
  Intent.setAction(TJIntent.JavaClass.ACTION_SEND);
  Intent.setType(StringToJString('text/plain'));

  // Especificar el texto que deseas imprimir
  Intent.putExtra(TJIntent.JavaClass.EXTRA_TEXT, StringToJString('Texto para imprimir'));

  // Enviar el Intent para imprimir
  Intent.putExtra(TJIntent.JavaClass.EXTRA_STREAM, nil);
  Intent.setPackage(StringToJString('com.android.bluetooth'));

  // Iniciar la actividad para imprimir
  SharedActivity.startActivity(Intent);
end;

end.

Código Delphi [-]
procedure TDevice.ListaDevices;
var
  Msg: string;
  I, B: Integer;

  ListaVinculados: TBluetoothDeviceList;
  LServices: TBluetoothServiceList;
begin

  try
  FBluetoothManager.Create;
   FBluetoothManager.EnableBluetooth;
    FBluetoothManager := TBluetoothManager.Current;
    if FBluetoothManager = nil
    then begin
         Close;
         end;

    FBluetoothManager.SocketTimeout := 100;

    BluetoothAdapter := FBluetoothManager.CurrentAdapter; // Aquí DA FALLO
     ShowMessage('Aquí');   exit;
    if BluetoothAdapter = nil
    then begin
         Close;
         end;

    ListaVinculados := FBluetoothManager.GetPairedDevices(BluetoothAdapter);
    if ListaVinculados = nil
    then begin
         Close;
         end;
         
   ComboDevices.Items.Clear; // Limpiamos cada vez el combo
   
    for I := 0 to ListaVinculados.Count - 1 do
    begin
      Impresora := ListaVinculados[i] as TBluetoothDevice;
      if Impresora.IsPaired then
      begin
        LServices := Impresora.GetServices;
        for B := 0 to LServices.Count - 1 do
        begin
          ServiceGUI := GUIDToString(LServices[b].UUID);
          Guid := LServices[b].UUID;
          ServiceName := LServices[b].Name;
        end;
      end
      else begin
           Close;
           end;
    ComboDevices.Items.Add(Impresora.DeviceName);
    end;
  except
   on E: Exception do
   begin
     Close;
   end;

 end;
 //FBluetoothManager.Destroy;
 if ComboDevices.Items.Count > 0 // Seleccionamos el primero
   then ComboDevices.ItemIndex := 0;

end;

Código Delphi [-]
// Hasta aquí llega
------------------------------------
  BluetoothAdapter := FBluetoothManager.CurrentAdapter; // Aquí DA FALLO
------------------------------------
// He probado con todos y con parte de ellos
const
  BlueTooth = 'android.permission.BLUETOOTH';
  BlueAdmin ='android.permission.BLUETOOTH_ADMIN';
  BlueConect='android.permission.BLUETOOTH_CONNECT';       //
  BlueScan = 'android.permission.BLUETOOTH_SCAN';           //
  BluePrint ='android.print.BLUETOOTH';
  BluePrivi ='android.permission.BLUETOOTH_PRIVILEGED';
  BlueDebug ='android.permission.BLUETOOTH_DEBUG';
  CorseLocate = 'android.permission.ACCESS_COARSE_LOCATION';
  FineLocate = 'android.permission.ACCESS_FINE_LOCATION';
  BlueSeting ='android.permission.BLUETOOTH_SETTINGS';
  BlueAdvert ='android.permission.BLUETOOTH_ADVERTISE';    //

Código Delphi [-]
unit Unit1;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
  FMX.Controls.Presentation, FMX.StdCtrls, FMX.ListBox;

type
  TForm1 = class(TForm)
    ComboBox1: TComboBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

procedure TForm1.Button1Click(Sender: TObject);
var
 I : Integer;
begin
  for I := 1 to 25
  do begin
       ComboBox1.Items.Add('Item Lento '+ I.ToString);
       Sleep(1000);
     end;

end;

end.

Código Delphi [-]
unit Unit1;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
  FMX.Controls.Presentation, FMX.StdCtrls, FMX.ListBox;

type
  TForm1 = class(TForm)
    ComboBox1: TComboBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

procedure TForm1.Button1Click(Sender: TObject);
var
 I : Integer;
begin
  for I := 1 to 25
  do begin
       ComboBox1.Items.Add('Item Lento '+ I.ToString);
       Sleep(1000);
     end;

end;

end.

Código Delphi [-]
unit Unit1;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
  FMX.Controls.Presentation, FMX.StdCtrls, FMX.ListBox;

type
  TForm1 = class(TForm)
    ComboBox1: TComboBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

procedure TForm1.Button1Click(Sender: TObject);
var
 ThreadSegPlano: TThread;
begin
  ThreadSegPlano:= TThread.CreateAnonymousThread(
  procedure 
  var 
    I : Integer; //Los contadores en hilos y procedimientos anonimos deben ser variables locales...
  begin
    for I := 1 to 25 do
    begin 
      //Siempre haz un Synchronize cuando modifiques el estado y propiedades de objetos visuales en este caso el Combo
      TThread.Synchronize(TThread.CurrentThread,
      procedure
      begin     
        ComboBox1.Items.Add('Item Lento '+ I.ToString);
      end);
      Sleep(1000); //Esta es tu tarea pesada, se le deja al hilo en segundo plano.....
    end;
  end);
  ThreadSegPlano.FreeOnTerminate:= True; //Liberar el hilo en memoria cuando termine
  //ThreadSegPlano.OnTerminate:= Aquí puedes asignarle un evento para cuando termine el hile como ocultar algun loading panel o mostrar un mensaje 
 // de carga finalizada, etc.
  ThreadSegPlano.Start;
end;

end.

Código Delphi [-]
 procedure BtnClick(Sender: TObject);
 var 
   Thread: TThread; //Declaras el hilo
 begin
   Thread:= TThread.CreateAnonymousThread(
    procedure 
    begin 
      TareaPesada;
       TThread.Synchronize(TThread.CurrentThread,
       procedure 
       begin
         //Modificar Objetos visuales Ej. Label.Text:= 'Hola';
       end);
    end);  
   Thread.FreeOnTerminate:= True;
   Thread.Start;
 end;

Código Delphi [-]
procedure TDevice.ListaDevices;
var
  Msg: string;
  I, B: Integer;

  ListaVinculados: TBluetoothDeviceList;
  LServices: TBluetoothServiceList;
begin

  try

    FBluetoothManager := TBluetoothManager.Current;
    if FBluetoothManager = nil
    then begin
         Close;
         end;

    FBluetoothManager.SocketTimeout := 100;

    BluetoothAdapter := FBluetoothManager.CurrentAdapter;

    if BluetoothAdapter = nil
    then begin
         Close;
         end;

    ListaVinculados := FBluetoothManager.GetPairedDevices(BluetoothAdapter);
    if ListaVinculados = nil
    then begin
         Close;
         end;

   ComboDevices.Items.Clear; // Limpiamos cada vez el combo

    for I := 0 to ListaVinculados.Count - 1 do
    begin
      Impresora := ListaVinculados[i] as TBluetoothDevice;
      if Impresora.IsPaired then
      begin
        LServices := Impresora.GetServices;
        for B := 0 to LServices.Count - 1 do
        begin
          ServiceGUI := GUIDToString(LServices[b].UUID);
          Guid := LServices[b].UUID;
          ServiceName := LServices[b].Name;
        end;
      end
      else begin
           Close;
           end;
    ComboDevices.Items.Add(Impresora.DeviceName);
    end;
  except
   on E: Exception do
   begin
     Close;
   end;

 end;
 FBluetoothManager.Free;
 BluetoothAdapter.Free;
 Guid.Empty;
 if ComboDevices.Items.Count > 0 // Seleccionamos el primero
   then ComboDevices.ItemIndex := 0;

end;

Código Delphi [-]
procedure TForm1.Button2Click(Sender: TObject);
begin
 Application.Terminate;
end;