exchange/app/Http/Controllers/SettingActiveBankController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\SettingActiveBank;

class SettingActiveBankController extends Controller
{
    public function index()
    {
        $active_bank_setting = SettingActiveBank::latest()->first();
        return response()->json($active_bank_setting, 200);
    }

    public function update(Request $request)
    {
        if($active_bank_setting = SettingActiveBank::latest()->first())
            $active_bank_setting->update($request->all());
        else
            $active_bank_setting = SettingActiveBank::create($request->all());

        return response()->json($active_bank_setting, 200);
    }
}