fix

app/Http/Controllers/SurveyQuestionController.php

@@ -61,14 +61,22 @@ public function adminShow($id)
     public function adminUsers(Request $request)
     {
         $perPage = max(1, min((int) $request->input('per_page', 20), 100));
+        $answered = $request->input('answered');
 
-        $users = User::select('id', 'first_name', 'last_name', 'age', 'gender', 'email', 'mobile', 'created_at', 'identifier')
+        $query = User::select('id', 'first_name', 'last_name', 'age', 'gender', 'email', 'mobile', 'created_at', 'identifier')
             ->withCount(['surveyAnswers as answers_count'])
             ->withCount(['surveyAnswers as questions_answered' => function ($q) {
                 $q->select(DB::raw('COUNT(DISTINCT survey_question_id)'));
             }])
-            ->orderByDesc('created_at')
-            ->paginate($perPage);
+            ->orderByDesc('created_at');
+
+        if ($answered === '1') {
+            $query->has('surveyAnswers');
+        } elseif ($answered === '0') {
+            $query->doesntHave('surveyAnswers');
+        }
+
+        $users = $query->paginate($perPage);
 
         return response()->json($users);
     }