add condition if wo not empty

app/Http/Controllers/Controller.php

 
             foreach ($response->data as $key => $r) {
                 $work_order = WorkOrder::where('wo', $r->wo)->first();
+
+                if(!empty($work_order)){
                 $form_submitted = Form::where('_id', $work_order->_id)->first();
 
                 $form_submitted->customer_category = $r->category;
                 $form_submitted->save();
+                }
             }
 
             return 'data inserted ';