Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color.fromARGB(255, 12, 12, 12),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Container(
            margin: const EdgeInsets.fromLTRB(0, 0, 20, 100),
            child: Stack(
              alignment: Alignment.center,
              children: [
                Container(
                  color: const Color.fromARGB(255, 27, 27, 27),
                  width: 200,
                  height: 50,
                  margin: const EdgeInsets.fromLTRB(0, 0, 0, 300),
                  alignment: Alignment.center,
                  child: Container(
                    margin: const EdgeInsets.fromLTRB(150, 0, 0, 0),
                    width: 34,
                    height: 34,
                    child: Stack(
                      children: [
                        OutlinedButton(
                          child: Icon(Icons.add),
                          onPressed: () {},
                          style: OutlinedButton.styleFrom(
                            backgroundColor: Colors.transparent,
                            side: BorderSide(
                                color: Color.fromARGB(255, 255, 106, 0),
                                width: 2),
                          ),
                        ),
                      ],
                    ),
                  ),
                ),

I am trying to center the " " Icon in the center of the button but for some reason it doesnt let me with margin and alignment and center widget am I doing something wrong? please help thank you.